diff --git a/src/assets/scss/main.scss b/src/assets/scss/main.scss
index 261b33b63..90521267c 100644
--- a/src/assets/scss/main.scss
+++ b/src/assets/scss/main.scss
@@ -84,6 +84,8 @@ $table-striped-row-even-hover-background-color:$link-light;
 $medium-modal-content-width: $modal-content-width * 1.4;
 $medium-modal-body-padding: 0 3em 2em 3em;
 
+$large-modal-content-width: $modal-content-width * 1.8;
+
 //$margin-right: 2 rem;
 
 // Import buefy before bulma
@@ -904,7 +906,7 @@ tr:nth-child(odd) td.db-filled {
   }
 }
 
-.experiment-observations-download-button {
+.sub-entity-dataset-modal, .experiment-observations-download-button {
   .modal {
     .modal-card {
       width: $medium-modal-content-width;
@@ -915,6 +917,17 @@ tr:nth-child(odd) td.db-filled {
   }
 }
 
+.sub-entity-dataset-modal {
+  .modal {
+    .modal-card {
+      width: $large-modal-content-width;
+      .modal-card-body {
+        padding: $medium-modal-body-padding;
+      }
+    }
+  }
+}
+
 .content {
   .pagination-list {
     margin-top: 0;
diff --git a/src/breeding-insight/dao/ExperimentDAO.ts b/src/breeding-insight/dao/ExperimentDAO.ts
index 83468197e..f937c5f2e 100644
--- a/src/breeding-insight/dao/ExperimentDAO.ts
+++ b/src/breeding-insight/dao/ExperimentDAO.ts
@@ -20,6 +20,7 @@ import * as api from "@/util/api";
 import {Result, ResultGenerator} from "@/breeding-insight/model/Result";
 import {Trial} from "@/breeding-insight/model/Trial.ts";
 import {DatasetModel} from "@/breeding-insight/model/DatasetModel";
+import {DatasetMetadata} from "@/breeding-insight/model/DatasetMetadata";
 
 export class ExperimentDAO {
 
@@ -38,6 +39,22 @@ export class ExperimentDAO {
             return ResultGenerator.err(error);
         }
     }
+
+    static async getDatasetMetadata(programId: string, experimentId: string): Promise<Result<Error, DatasetMetadata[]>> {
+        const config: any = {};
+        config.url = `${process.env.VUE_APP_BI_API_V1_PATH}/programs/${programId}/experiments/${experimentId}/datasets`;
+        config.method = 'get';
+        config.programId = programId;
+        config.experimentId = experimentId;
+        try {
+            const res = await api.call(config) as Response;
+            let { result } = res.data;
+            return ResultGenerator.success(result);
+        } catch (error) {
+            return ResultGenerator.err(error);
+        }
+    }
+
     static async getDatasetById(programId: string, experimentId: string, datasetId: string, stats: boolean): Promise<Result<Error, DatasetModel>> {
         const config: any = {};
         config.url = `${process.env.VUE_APP_BI_API_V1_PATH}/programs/${programId}/experiments/${experimentId}/dataset/${datasetId}`;
@@ -57,4 +74,19 @@ export class ExperimentDAO {
         }
     }
 
+    static async createSubEntityDataset(programId: string, experimentId: string, name: string, repeatedMeasures: number): Promise<Result<Error, DatasetModel>> {
+        const config: any = {};
+        config.url = `${process.env.VUE_APP_BI_API_V1_PATH}/programs/${programId}/experiments/${experimentId}/dataset`;
+        config.method = 'post';
+        config.programId = programId;
+        config.experimentId = experimentId;
+        config.data = {name: name, repeatedMeasures: repeatedMeasures}  // Corresponds to SubEntityDatasetRequest in bi-api.
+        try {
+            const res = await api.call(config) as Response;
+            let { result } = res.data;
+            return ResultGenerator.success(result);
+        } catch (error) {
+            return ResultGenerator.err(error);
+        }
+    }
 }
diff --git a/src/breeding-insight/model/ExperimentDatasetOption.ts b/src/breeding-insight/model/DatasetMetadata.ts
similarity index 65%
rename from src/breeding-insight/model/ExperimentDatasetOption.ts
rename to src/breeding-insight/model/DatasetMetadata.ts
index 048b4e301..932e55935 100644
--- a/src/breeding-insight/model/ExperimentDatasetOption.ts
+++ b/src/breeding-insight/model/DatasetMetadata.ts
@@ -15,16 +15,21 @@
  * limitations under the License.
  */
 
-import {SelectOption} from "@/breeding-insight/model/SelectOption";
+import {Observation} from "@/breeding-insight/model/Observation";
+import {ObservationUnit} from "@/breeding-insight/model/ObservationUnit";
+import {ObservationVariable} from "@/breeding-insight/model/ObservationVariable";
 
-export class ExperimentDatasetOption implements SelectOption<string, string> {
-    static observations = new ExperimentDatasetOption("Observation Dataset", "observations");
-
-    name: string;
+export class DatasetMetadata {
     id: string;
+    name: string;
+    level: number;
 
-    constructor(name: string, id: string) {
-        this.name = name;
+    constructor(id: string,
+                name: string,
+                level: number
+    ) {
         this.id = id;
+        this.name = name;
+        this.level = level;
     }
 }
\ No newline at end of file
diff --git a/src/breeding-insight/model/DatasetModel.ts b/src/breeding-insight/model/DatasetModel.ts
index 1acd5016b..37d5abe82 100644
--- a/src/breeding-insight/model/DatasetModel.ts
+++ b/src/breeding-insight/model/DatasetModel.ts
@@ -28,7 +28,6 @@ export class DatasetModel {
   additionalInfo?: any;
 
 
-
   constructor(id: string,
               experimentId: string,
               data: Observation[],
diff --git a/src/breeding-insight/model/ExperimentExportOptions.ts b/src/breeding-insight/model/ExperimentExportOptions.ts
index 6476c079a..41a9f3c2b 100644
--- a/src/breeding-insight/model/ExperimentExportOptions.ts
+++ b/src/breeding-insight/model/ExperimentExportOptions.ts
@@ -22,7 +22,7 @@ import {ExperimentDatasetOption} from "@/breeding-insight/model/ExperimentDatase
 export class ExperimentExportOptions {
 
     public fileExtension: string = FileTypeOption.xls.id;
-    public dataset: string = ExperimentDatasetOption.observations.id;
+    public datasetId: string;
     public environments: string[] = [];
     public allEnvironments: boolean = false;
     public includeTimestamps: string = 'No';
diff --git a/src/breeding-insight/model/SubEntityDatasetNewRequest.ts b/src/breeding-insight/model/SubEntityDatasetNewRequest.ts
new file mode 100644
index 000000000..4f5c384d1
--- /dev/null
+++ b/src/breeding-insight/model/SubEntityDatasetNewRequest.ts
@@ -0,0 +1,31 @@
+/*
+ * See the NOTICE file distributed with this work for additional information
+ * regarding copyright ownership.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+import {Observation} from "@/breeding-insight/model/Observation";
+import {ObservationUnit} from "@/breeding-insight/model/ObservationUnit";
+import {ObservationVariable} from "@/breeding-insight/model/ObservationVariable";
+
+export class SubEntityDatasetNewRequest {
+    name: string;
+    repeatedMeasures: number;
+
+
+    constructor(name: string, repeatedMeasures: string) {
+        this.name = name;
+        this.repeatedMeasures = repeatedMeasures;
+    }
+}
\ No newline at end of file
diff --git a/src/breeding-insight/service/ExperimentService.ts b/src/breeding-insight/service/ExperimentService.ts
index 8de5d4f59..f0fe083cb 100644
--- a/src/breeding-insight/service/ExperimentService.ts
+++ b/src/breeding-insight/service/ExperimentService.ts
@@ -16,9 +16,12 @@
  */
 
 import {ExperimentDAO} from "@/breeding-insight/dao/ExperimentDAO";
-import {Trial} from "@/breeding-insight/model/Trial.ts";
+import {Trial} from "@/breeding-insight/model/Trial";
 import {Result, ResultGenerator} from "@/breeding-insight/model/Result";
 import {DatasetModel} from "@/breeding-insight/model/DatasetModel";
+import {DatasetMetadata} from "@/breeding-insight/model/DatasetMetadata";
+import {SubEntityDatasetNewRequest} from "@/breeding-insight/model/SubEntityDatasetNewRequest";
+import {BrAPIUtils} from "@/breeding-insight/utils/BrAPIUtils";
 
 export class ExperimentService {
 
@@ -36,4 +39,36 @@ export class ExperimentService {
         return await ExperimentDAO.getDatasetById(programId,experimentId, datasetId, true);
     }
 
+    static async createSubEntityDataset(programId: string, experimentId: string, subEntityRequest: SubEntityDatasetNewRequest): Promise<Result<Error, DatasetModel>> {
+        if (!programId) {
+            return ResultGenerator.err(new Error('Missing or invalid program id'));
+        }
+        return await ExperimentDAO.createSubEntityDataset(programId, experimentId, subEntityRequest.name, subEntityRequest.repeatedMeasures);
+    }
+
+    static async getDatasetMetadata(programId: string, experimentId: string): Promise<Result<Error, DatasetMetadata[]>> {
+        if (!programId) {
+            return ResultGenerator.err(new Error('Missing or invalid program id'));
+        }
+        return await ExperimentDAO.getDatasetMetadata(programId, experimentId);
+    }
+
+    static async getDatasetMetadataByTrial(programId: string, trial: Trial): Promise<Result<Error, DatasetMetadata[]>> {
+        if (!programId) {
+            return ResultGenerator.err(new Error('Missing or invalid program id'));
+        }
+        if (!trial) {
+            return ResultGenerator.err(new Error('Missing or invalid trial'));
+        }
+        if (!trial.externalReferences) {
+            return ResultGenerator.err(new Error('Trial is missing external references'));
+        }
+        // Try to get the /trials external reference.
+        let externalReferenceId = BrAPIUtils.getBreedingInsightId(trial.externalReferences, '/trials');
+        // Throw if trial is missing ExternalReferenceId.
+        if (!externalReferenceId) {
+            return ResultGenerator.err(new Error("Trial is missing external reference."));
+        }
+        return await ExperimentDAO.getDatasetMetadata(programId, externalReferenceId);
+    }
 }
diff --git a/src/components/experiments/ExperimentObservationsDownloadModal.vue b/src/components/experiments/ExperimentObservationsDownloadModal.vue
index 18591e0df..653204d8d 100644
--- a/src/components/experiments/ExperimentObservationsDownloadModal.vue
+++ b/src/components/experiments/ExperimentObservationsDownloadModal.vue
@@ -20,7 +20,7 @@
     v-bind:unique-id="trialId"
     v-bind:modal-title="modalTitle"
     v-bind:download="downloadList"
-    v-bind:active="active && loadingStudyOptionsComplete"
+    v-bind:active="active && loadingStudyOptionsComplete && loadingDatasetOptionsComplete"
     modal-class="experiment-observations-download-button"
     v-on:deactivate="resetExportOptions"
   >
@@ -37,7 +37,7 @@
               <div class="select">
                 <select
                   v-bind:id="`dataset-select-${trialId}`"
-                  v-model="fileOptions.dataset"
+                  v-model="fileOptions.datasetId"
                 >
                   <option
                     v-for="option in datasetOptions"
@@ -157,7 +157,6 @@ import {mapGetters} from "vuex";
 import {Program} from "@/breeding-insight/model/Program";
 import {ExperimentExportOptions} from "@/breeding-insight/model/ExperimentExportOptions";
 import {FileTypeOption} from "@/breeding-insight/model/FileTypeOption";
-import {ExperimentDatasetOption} from "@/breeding-insight/model/ExperimentDatasetOption";
 import {AlertTriangleIcon} from 'vue-feather-icons';
 import {Trial} from "@/breeding-insight/model/Trial";
 import {Metadata} from "@/breeding-insight/model/BiResponse";
@@ -165,7 +164,9 @@ import {Study} from "@/breeding-insight/model/Study";
 import {StudyService} from "@/breeding-insight/service/StudyService";
 import {Result} from "@/breeding-insight/model/Result";
 import {BrAPIUtils} from "@/breeding-insight/utils/BrAPIUtils";
-import DownloadModal from "@/components/DownloadModal.vue";
+import DownloadModal from "@/components/modals/DownloadModal.vue";
+import {DatasetMetadata} from "@/breeding-insight/model/DatasetMetadata";
+import {ExperimentService} from "@/breeding-insight/service/ExperimentService";
 
 @Component({
   mixins: [validationMixin],
@@ -186,20 +187,25 @@ export default class ExperimentObservationsDownloadModal extends Vue {
   experiment!: Trial;
   @Prop()
   modalTitle?: string;
+  @Prop()
+  defaultDatasetId?: string;
 
   private activeProgram?: Program;
   private fileOptions: ExperimentExportOptions = new ExperimentExportOptions();
   private showEnvironmentsValidationError: boolean = false;
   private fileExtensionOptions: object[] = Object.values(FileTypeOption);
-  private datasetOptions: object[] = Object.values(ExperimentDatasetOption);
+  private datasetOptions: DatasetMetadata[] = [];
   private environmentOptions: object[] = [];
   private loadingStudyOptionsComplete: boolean = false;
+  private loadingDatasetOptionsComplete: boolean = false;
 
   @Watch('experiment', {immediate: true})
   onExperimentChanged() {
-    // reset loading flag
+    // Reset loading flags.
     this.loadingStudyOptionsComplete = false;
+    this.loadingDatasetOptionsComplete = false;
     this.getStudyOptions();
+    this.getDatasetOptions();
   }
 
   async getStudyOptions() {
@@ -217,6 +223,34 @@ export default class ExperimentObservationsDownloadModal extends Vue {
     }
   }
 
+  async getDatasetOptions() {
+    // Fetch all datasets available for this experiment.
+    try {
+      const response: Result<Error, DatasetMetadata[]> = await ExperimentService.getDatasetMetadataByTrial(this.activeProgram!.id!, this.experiment!);
+      if (response.isErr()) {
+        throw response.value;
+      }
+      this.datasetOptions = response.value;
+
+      this.setDefaultDatasetOption();
+
+      this.loadingDatasetOptionsComplete = true;
+    } catch (err) {
+      // Display error that datasets cannot be loaded
+      this.$emit('show-error-notification', 'Error while trying to load datasets');
+      throw err;
+    }
+  }
+
+  setDefaultDatasetOption() {
+    // Set default selected dataset to property if provided, fall back to first in list of options.
+    if (this.defaultDatasetId !== undefined) {
+      this.fileOptions.datasetId = this.defaultDatasetId;
+    } else if (this.datasetOptions.length > 0){
+      this.fileOptions.datasetId = this.datasetOptions[0].id;
+    }
+  }
+
   downloadList(): boolean {
     // Validate selected options.
     if (this.validateOptions()) {
@@ -229,8 +263,8 @@ export default class ExperimentObservationsDownloadModal extends Vue {
             + this.trialId
             + '/export?fileExtension='
             + this.fileOptions.fileExtension
-            + '&dataset='
-            + this.fileOptions.dataset
+            + '&datasetId='
+            + this.fileOptions.datasetId
             + (this.fileOptions.allEnvironments ? '' : ('&environments=' + this.fileOptions.environments))
             + '&includeTimestamps='
             + this.fileOptions.timestampsTrueFalseString(),
@@ -246,6 +280,8 @@ export default class ExperimentObservationsDownloadModal extends Vue {
     this.$emit('deactivate');
     // Reset file export options.
     this.fileOptions = new ExperimentExportOptions();
+    // Make sure default dataset option is selected.
+    this.setDefaultDatasetOption();
     // Reset validation state.
     this.showEnvironmentsValidationError = false;
   }
diff --git a/src/components/experiments/ExperimentsObservationsTable.vue b/src/components/experiments/ExperimentsObservationsTable.vue
index 1293f1509..4e8568ce6 100644
--- a/src/components/experiments/ExperimentsObservationsTable.vue
+++ b/src/components/experiments/ExperimentsObservationsTable.vue
@@ -19,12 +19,13 @@
   <section id="experimentsObservationsTableLabel">
 
     <ExperimentObservationsDownloadModal
-        v-bind:experiment="downloadExperiment"
-        v-bind:modal-title="downloadModalTitle"
-        v-bind:trial-id="downloadTrialId"
-        v-bind:active="downloadModalActive"
-        v-on:show-error-notification ="$emit('show-error-notification', $event)"
-        v-on:deactivate="downloadModalActive = false"
+      v-if="downloadModalActive"
+      v-bind:experiment="downloadExperiment"
+      v-bind:modal-title="downloadModalTitle"
+      v-bind:trial-id="downloadTrialId"
+      v-bind:active="downloadModalActive"
+      v-on:show-error-notification="$emit('show-error-notification', $event)"
+      v-on:deactivate="downloadModalActive = false"
     />
 
     <div class="is-clearfix"></div>
@@ -42,7 +43,7 @@
       v-on:search="initSearch"
     >
       <b-table-column label="Title" field="name" cell-class="fixed-width-wrapped" sortable v-slot="props" :th-attrs="(column) => ({scope:'col'})" searchable>
-        <router-link v-bind:to="{name: 'experiment-details', params: {programId: activeProgram.id, experimentId: BrAPIUtils.getBreedingInsightId(props.row.data.externalReferences,'/trials')}}">
+        <router-link v-bind:to="{name: 'experiment_dataset', params: {datasetId: getDefaultDataset(props.row.data).id, programId: activeProgram.id, experimentId: BrAPIUtils.getBreedingInsightId(props.row.data.externalReferences,'/trials')}}">
           {{ props.row.data.trialName }}
         </router-link>
 
@@ -58,7 +59,7 @@
       </b-table-column>
       <b-table-column label="Datasets" cell-class="fixed-width-wrapped" sortable v-slot="props" :th-attrs="(column) => ({scope:'col'})">
         <template v-for="dataset in props.row.data.additionalInfo.datasets">
-          <span v-bind:key="dataset" class="tag is-info is-normal mr-1">{{ dataset }}</span>
+          <span v-bind:key="dataset.id" class="tag is-info is-normal mr-1">{{ dataset.name }}</span>
         </template>
       </b-table-column>
       <b-table-column field="data.listDbId" sortable v-slot="props" :th-attrs="(column) => ({scope:'col'})">
@@ -95,6 +96,7 @@ import {PaginationController} from "@/breeding-insight/model/view_models/Paginat
 import {UPDATE_EXPERIMENT_SORT} from "@/store/sorting/mutation-types";
 import {BrAPIUtils} from "@/breeding-insight/utils/BrAPIUtils";
 import ExperimentObservationsDownloadModal from "@/components/experiments/ExperimentObservationsDownloadModal.vue";
+import {DatasetMetadata} from "@/breeding-insight/model/DatasetMetadata";
 
 @Component({
   mixins: [validationMixin],
@@ -141,8 +143,8 @@ export default class ExperimentsObservationsTable extends Vue {
 
   private downloadModalActive: boolean = false;
   private downloadExperiment?: Trial = new Trial();
-  private downloadModalTitle?: string = 'undefined';
-  private downloadTrialId?: string = 'undefined';
+  private downloadModalTitle?: string;
+  private downloadTrialId?: string;
 
   mounted() {
     this.experimentCallStack = new CallStack(this.experimentsFetch(
@@ -192,6 +194,17 @@ export default class ExperimentsObservationsTable extends Vue {
     }
   }
 
+  // TODO: move to utilitiy?
+  getDefaultDataset(experiment: Trial): DatasetMetadata | null {
+    // Get default observation level.
+    if (experiment.additionalInfo !== null)
+    {
+      // One and only one top level dataset is always expected, and it will have level = 0.
+      return experiment.additionalInfo.datasets.find((x: DatasetMetadata) => x.level == 0) || null;
+    }
+    return null;
+  }
+
   getStatus(active: boolean){
     if (active) {
       return "active";
@@ -201,10 +214,10 @@ export default class ExperimentsObservationsTable extends Vue {
   }
 
   openDownloadModal(experiment: Trial) {
-    this.downloadModalActive = true;
     this.downloadExperiment = experiment;
     this.downloadModalTitle = "Download " + experiment.trialName;
     this.downloadTrialId = BrAPIUtils.getBreedingInsightId(experiment.externalReferences!, '/trials');
+    this.downloadModalActive = true;
   }
 
   setSort(field: string, order: string) {
diff --git a/src/components/forms/BaseFieldWrapper.vue b/src/components/forms/BaseFieldWrapper.vue
index 7f9a4b68a..d412a920d 100644
--- a/src/components/forms/BaseFieldWrapper.vue
+++ b/src/components/forms/BaseFieldWrapper.vue
@@ -108,6 +108,9 @@
             case 'alpha':
               validationMap['message'] = `${this.fieldName} must use only alphabetic characters.`;
               break;
+            case 'between':
+              validationMap['message'] = `${this.fieldName} must be between ${this.validations.$params.between.min} and ${this.validations.$params.between.max}.`;
+              break;
             default:
               // For now assume other possibility is a specific format
               validationMap['message'] = `${this.fieldName} must be in ${validation} format`;
diff --git a/src/components/DownloadModal.vue b/src/components/modals/DownloadModal.vue
similarity index 100%
rename from src/components/DownloadModal.vue
rename to src/components/modals/DownloadModal.vue
diff --git a/src/components/modals/SubEntityDatasetModal.vue b/src/components/modals/SubEntityDatasetModal.vue
new file mode 100644
index 000000000..5c7a04f55
--- /dev/null
+++ b/src/components/modals/SubEntityDatasetModal.vue
@@ -0,0 +1,158 @@
+<!--
+- See the NOTICE file distributed with this work for additional information
+- regarding copyright ownership.
+-
+- Licensed under the Apache License, Version 2.0 (the "License");
+- you may not use this file except in compliance with the License.
+- You may obtain a copy of the License at
+-
+-     http://www.apache.org/licenses/LICENSE-2.0
+-
+- Unless required by applicable law or agreed to in writing, software
+- distributed under the License is distributed on an "AS IS" BASIS,
+- WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+- See the License for the specific language governing permissions and
+- limitations under the License.
+-->
+
+<template>
+  <section
+    v-bind:id="'subEntityDatasetModal-' + uniqueId"
+    class="sub-entity-dataset-modal"
+  >
+    <BaseModal
+      v-bind:active.sync="active"
+      v-bind:title="modalTitle"
+      v-on:deactivate="deactivateModal"
+    >
+      <article class="media">
+        <div class="media-content">
+          <div class="content">
+            <h2 class="is-5 title model-header">
+              {{ modalTitle }}
+            </h2>
+          </div>
+        </div>
+      </article>
+      <DataForm
+        v-if="true"
+        v-bind:row-validations="formValidations"
+        v-bind:record.sync="newSubEntity"
+        v-bind:data-form-state="newSubEntityFormState"
+        v-on:submit="invokeCreate"
+        v-on:cancel="deactivateModal"
+        v-on:show-error-notification="$emit('show-error-notification', $event)"
+      >
+        <template v-slot="validations">
+          <div class="message is-success">
+            <div class="message-body">
+              Prepare a dataset for repeated observations within {{ defaultObservationLevel }}.
+            </div>
+          </div>
+          <div class="columns is-multiline mb-4">
+            <!-- Dataset Name Select -->
+            <div class="column is-6">
+              <AutoCompleteField
+                id="dataset-name-autocomplete"
+                v-model="newSubEntity.name"
+                v-bind:options="datasetNameOptions"
+                v-bind:validations="validations.name"
+                v-bind:field-name="'Sub-Entity Name'"
+                v-bind:field-help="'Create new or reuse a previously described sub-observation unit.'"
+                v-bind:show-label="true"
+              />
+            </div>
+            <!-- Dataset Repeated Measures -->
+            <div class="column is-6">
+              <BasicInputField
+                id="dataset-repeated-measures"
+                v-model="newSubEntity.repeatedMeasures"
+                v-bind:validations="validations.repeatedMeasures"
+                v-bind:field-name="'Repeated Measures'"
+                v-bind:field-help="'Maximum expected'"
+              />
+            </div>
+          </div>
+        </template>
+      </DataForm>
+    </BaseModal>
+  </section>
+</template>
+
+
+<script lang="ts">
+import {Component, Vue, Prop} from "vue-property-decorator";
+import {validationMixin} from "vuelidate";
+import BaseModal from "@/components/modals/BaseModal.vue";
+import AutoCompleteField from "@/components/forms/AutoCompleteField.vue";
+import BasicInputField from "@/components/forms/BasicInputField.vue";
+import {Trial} from "@/breeding-insight/model/Trial";
+import {between, maxLength, minLength, required, integer} from 'vuelidate/lib/validators'
+import BasicSelectField from "@/components/forms/BasicSelectField.vue";
+import DataForm from "@/components/forms/DataForm.vue";
+import {DatasetMetadata} from "@/breeding-insight/model/DatasetMetadata";
+import {SubEntityDatasetNewRequest} from "@/breeding-insight/model/SubEntityDatasetNewRequest";
+import {DataFormEventBusHandler} from "@/components/forms/DataFormEventBusHandler";
+
+@Component({
+  mixins: [validationMixin],
+  components: {DataForm, BasicSelectField, BasicInputField, AutoCompleteField, BaseModal}
+})
+export default class SubEntityDatasetModal extends Vue {
+
+  @Prop()
+  uniqueId!: string;
+  @Prop()
+  modalTitle?: string;
+  @Prop()
+  modalClass?: string;
+  @Prop()
+  create!: (SubEntityDatasetNewRequest) => Promise<boolean>;
+  @Prop()
+  active!: boolean;
+  @Prop()
+  datasetNameOptions?: string[];
+  @Prop()
+  experiment!: Trial;
+  @Prop()
+  defaultObservationLevel?: string;
+
+  // Reactive, private (would not be reactive if declared without initial values).
+  private newSubEntity: SubEntityDatasetNewRequest = new SubEntityDatasetNewRequest();
+  private newSubEntityFormState: DataFormEventBusHandler = new DataFormEventBusHandler();
+
+  // Form validations.
+  formValidations = {
+    name: {
+      required,
+      minLength: minLength(1),
+      maxLength: maxLength(200)},
+    repeatedMeasures: {
+      required,
+      integer,
+      between: between(1, 50),  // Note: capped at 50 for performance considerations.
+    }
+  }
+
+  deactivateModal(){
+    // Reset form state.
+    this.newSubEntity = new SubEntityDatasetNewRequest();
+    // Emit deactivate event.
+    this.$emit('deactivate');
+  }
+
+  async invokeCreate(){
+    try {
+      // Invoke the create prop, which returns true if create succeeded.
+      await this.create(this.newSubEntity)
+      // Close and deactivate modal.
+      this.deactivateModal();
+    } catch (error) {
+      this.$emit('show-error-notification', 'Error creating sub-entity dataset.');
+    } finally {
+      this.newSubEntityFormState.bus.$emit(DataFormEventBusHandler.SAVE_COMPLETE_EVENT);
+    }
+  }
+
+}
+</script>
\ No newline at end of file
diff --git a/src/router/index.ts b/src/router/index.ts
index cfec7e57b..afbd08f38 100644
--- a/src/router/index.ts
+++ b/src/router/index.ts
@@ -351,14 +351,15 @@ const routes = [
       layout: layouts.userSideBar
     },
     component: ExperimentDetails,
-    redirect: (to: Route) => ({name: 'experiment_obs_dataset', params: {datasetId: 'observation', programId: to.params.programId, experimentId: to.params.experimentId}}),
+    // TODO: test redirect with datasetId: null.
+    redirect: (to: Route) => ({name: 'experiment_dataset', params: {datasetId: null, programId: to.params.programId, experimentId: to.params.experimentId}}),
     beforeEnter: processProgramNavigation,
     children: [
       {
         path: 'dataset/:datasetId',
-        name: 'experiment_obs_dataset',
+        name: 'experiment_dataset',
         meta: {
-          title: 'Observation Dataset',
+          title: `Datasets`,
           layout: layouts.userSideBar
         },
         component: Dataset,
diff --git a/src/views/experiments-and-observations/ExperimentDetails.vue b/src/views/experiments-and-observations/ExperimentDetails.vue
index c6abd4e9d..3f0d7b90d 100644
--- a/src/views/experiments-and-observations/ExperimentDetails.vue
+++ b/src/views/experiments-and-observations/ExperimentDetails.vue
@@ -29,10 +29,22 @@
         v-bind:modal-title="`Download ${experiment.trialName}`"
         v-bind:trial-id="experimentUUID"
         v-bind:active="downloadModalActive"
-        v-on:show-error-notification ="$emit('show-error-notification', $event)"
+        v-on:show-error-notification="$emit('show-error-notification', $event)"
         v-on:deactivate="downloadModalActive = false"
     />
 
+    <SubEntityDatasetModal
+        v-bind:experiment="experiment"
+        v-bind:default-observation-level="experimentObservationUnit"
+        v-bind:dataset-name-options="datasetNameOptions"
+        v-bind:modal-title="`Create Sub-Entity Dataset`"
+        v-bind:trial-id="experimentUUID"
+        v-bind:active="subEntityModalActive"
+        v-bind:create="createSubEntityDataset"
+        v-on:show-error-notification="$emit('show-error-notification', $event)"
+        v-on:deactivate="subEntityModalActive = false"
+    />
+
     <div v-if="!experimentLoading && experiment!=null">
 
       <div class="columns is-multiline is-align-items-stretch mt-4">
@@ -61,9 +73,10 @@
           <ActionMenu v-bind:is-primary="true"
                       v-bind:id="'manage-experiment-dropdown-button'"
                       v-bind:button-text="'Manage Experiment'"
-                      v-bind:action-menu-items=actions
+                      v-bind:action-menu-items="actions"
                       v-on:import-file="importFile()"
                       v-on:download-file="downloadFile()"
+                      v-on:create-sub-entity-dataset="openSubEntityModal()"
           />
         </article>
       </div>
@@ -73,11 +86,14 @@
       <nav class="tabs is-boxed">
         <ul>
           <router-link
-              v-bind:to="{name: 'experiment_obs_dataset', params: {programId: activeProgram.id, experimentId: experimentUUID, datasetId: 'observation'}}"
-              tag="li" active-class="is-active">
-            <a>Observation Dataset</a>
+            v-for="dataset in datasetMetadata"
+            v-bind:key="dataset.id"
+            v-bind:to="{name: 'experiment_dataset', params: {programId: activeProgram.id, experimentId: experimentUUID, datasetId: dataset.id}}"
+            tag="li"
+            active-class="is-active"
+          >
+            <a>{{ dataset.name }}</a>
           </router-link>
-          <!--TODO: Will need to loop through a list of datasets and add a tab for each.-->
         </ul>
       </nav>
     </section>
@@ -104,9 +120,14 @@ import ProgramsBase from "@/components/program/ProgramsBase.vue";
 import ActionMenu from "@/components/layouts/menus/ActionMenu.vue";
 import {ActionMenuItem} from "@/breeding-insight/model/ActionMenuItem";
 import ExperimentObservationsDownloadModal from "@/components/experiments/ExperimentObservationsDownloadModal.vue";
+import SubEntityDatasetModal from "@/components/modals/SubEntityDatasetModal.vue";
+import {DatasetMetadata} from "@/breeding-insight/model/DatasetMetadata";
+import {SubEntityDatasetNewRequest} from "@/breeding-insight/model/SubEntityDatasetNewRequest";
+import {DatasetModel} from "@/breeding-insight/model/DatasetModel";
 
 @Component({
   components: {
+    SubEntityDatasetModal,
     PlusCircleIcon,
     ExperimentObservationsDownloadModal,
     ActionMenu
@@ -125,14 +146,18 @@ export default class ExperimentDetails extends ProgramsBase {
   private experiment: Trial;
   private experimentLoading: boolean = true;
   private downloadModalActive: boolean = false;
+  private subEntityModalActive: boolean = false;
+  private datasetMetadata: DatasetMetadata[] = [];
 
   private actions: ActionMenuItem[] = [
       new ActionMenuItem('experiment-import-file', 'import-file', 'Import file'),
-      new ActionMenuItem('experiment-download-file', 'download-file', 'Download file')
+      new ActionMenuItem('experiment-download-file', 'download-file', 'Download file'),
+      new ActionMenuItem('experiment-create-sub-entity-dataset', 'create-sub-entity-dataset', 'Create Sub-Entity Dataset')
   ];
 
   mounted () {
     this.getExperiment();
+    this.getDatasetMetadata();
   }
 
   private importFile() {
@@ -148,6 +173,20 @@ export default class ExperimentDetails extends ProgramsBase {
     this.downloadModalActive = true;
   }
 
+  private async createSubEntityDataset(subEntityRequest: SubEntityDatasetNewRequest): Promise<boolean> {
+    console.log("createSubEntityDataset invoked with arguments: datasetName=" + subEntityRequest.name + ", repeatedMeasures=" + subEntityRequest.repeatedMeasures);
+    const response: Result<Error, DatasetModel> = await ExperimentService.createSubEntityDataset(this.activeProgram!.id!, this.experimentUUID, subEntityRequest);
+    if (response.isErr()) {
+      throw response.value;
+    }
+    await this.$router.push({name: 'experiment_dataset', params: {datasetId: response.value.id, programId: this.activeProgram!.id!, experimentId: this.experimentUUID}});
+    return true;
+  }
+
+  private openSubEntityModal() {
+    this.subEntityModalActive = true;
+  }
+
   get experimentUUID(): string {
     return this.$route.params.experimentId;
   }
@@ -179,6 +218,19 @@ export default class ExperimentDetails extends ProgramsBase {
   //   return this.experiment.additionalInfo.environmentsCount;
   // }
 
+  get datasetNameOptions(): String[] {
+    // TODO: [BI-2182] fetch and return all sub-entity names for experiments in this program, excluding the current experiment.
+    // TODO: [BI-2182] exclude top level dataset names.
+    return [];
+  }
+
+  get experimentObservationUnit(): string | null {
+    if (this.experiment && this.experiment.additionalInfo) {
+      return this.experiment.additionalInfo.defaultObservationLevel;
+    }
+    return null;
+  }
+
   @Watch('$route')
   async getExperiment () {
     this.experimentLoading = true;
@@ -196,5 +248,21 @@ export default class ExperimentDetails extends ProgramsBase {
       this.experimentLoading = false;
     }
   }
+
+  // Get metadata for all datasets available in this experiment.
+  @Watch('$route')
+  async getDatasetMetadata(): DatasetMetadata[] {
+    try {
+      const response: Result<Error, DatasetMetadata[]> = await ExperimentService.getDatasetMetadata(this.activeProgram!.id!, this.experimentUUID, true);
+      if (response.isErr()) {
+        throw response.value;
+      }
+      this.datasetMetadata = response.value;
+    } catch (err) {
+      // Display error that experiment cannot be loaded
+      this.$emit('show-error-notification', 'Error while trying to load datasets');
+      throw err;
+    }
+  }
 }
 </script>
\ No newline at end of file
diff --git a/src/views/import/Dataset.vue b/src/views/import/Dataset.vue
index e0411596e..237253c3c 100644
--- a/src/views/import/Dataset.vue
+++ b/src/views/import/Dataset.vue
@@ -307,6 +307,7 @@ import {Metadata} from "@/breeding-insight/model/BiResponse";
 import {StudyService} from "@/breeding-insight/service/StudyService";
 import {BrAPIService, BrAPIType} from '@/breeding-insight/service/BrAPIService';
 import {SortOrder} from "@/breeding-insight/model/Sort";
+import {DatasetMetadata} from "@/breeding-insight/model/DatasetMetadata";
 
 @Component({
   components: {
@@ -615,8 +616,9 @@ export default class Dataset extends ProgramsBase {
       if (experimentResult.isErr()) throw experimentResult.value;
       this.experiment = experimentResult.value;
 
-      if (this.datasetId === 'observation') {
-        this.resultDatasetId = this.experiment.additionalInfo.observationDatasetId;
+      if (this.datasetId === null) {
+        // Get top level dataset id.
+        this.resultDatasetId = this.experiment.additionalInfo.datasets.find((x: DatasetMetadata) => x.level == 0).id || null;
       } else {
         this.resultDatasetId = this.datasetId;
       }