Applying [yshift] to a group of elements?

[calvinpark]

This is the graph I want to draw.

Since mytag sits above u1, u1 had to be shifted down.
Since u1 has been shifted down, every element around it also had to be shifted down.

  \gitDAG[grow right sep = 1em]{
    m1 -- { m2 ,
            u1[yshift=-2em] -- u2[yshift=-2em],
            t1[yshift=-2em] -- t2[yshift=-2em]
          }
    };
  \gittag
    {mytag}       % node name and text 
    {above=of u1} % node placement
    {u1}          % target

Is there a better way to draw this graph, without applying yshift to every element?

Thank you

[jubobs]

I can't think of a very convenient way of reducing code duplication (yshift=-2em), in this case. The closest thing is to use branch down, as shown below:

\gitDAG[grow right sep = 1em, branch down = 5em]{
    m1 -- {m2 ,
            u1 -- u2,
            t1 -- t2
          }
   };
  \gittag
    {mytag}       % node name and text 
    {above=of u1} % node placement
    {u1}          % target

[calvinpark]

Thank you, that was helpful.
It's too bad that there's no way to group elements.