I use the following:
    \runMPgraphicsfalse
      \usemodule[chart]

    \setupFLOWcharts[
      bodyfont={PT Serif,rm,10pt},
    ]

    \starttext

    \startFLOWchart[subversion]
      \startFLOWcell
        \location   {2,1}
        \name       {test}
        \shape      {34}
        \text       {test}
      \stopFLOWcell

      \startFLOWcell
        \location   {3,1}
        \name       {production}
        \shape      {34}
        \text       {production}
      \stopFLOWcell

      \startFLOWcell
        \connection [bt]{progA}
        \connection [rl]{branches}
        \connection [tl]{test}
        \location   {1,2}
        \name       {trunk}
        \shape      {34}
        \text       {trunk}
      \stopFLOWcell

      \startFLOWcell
        \connection [bpt]{progA}
        \connection [lr]{trunk}
        \connection [rl]{tags}
        \location   {2,2}
        \name       {branches}
        \shape      {34}
        \text       {branches}
      \stopFLOWcell

      \startFLOWcell
        \connection [tb]{production}
        \location   {3,2}
        \name       {tags}
        \shape      {34}
        \text       {tags}
      \stopFLOWcell

      \startFLOWcell
        \connection [tb]{trunk}
        \connection [ptb]{branches}
        \location   {1,3}
        \name       {progA}
        \shape      {34}
        \text       {Programmer A}
      \stopFLOWcell

      \startFLOWcell
        \location   {2,3}
        \name       {progB}
        \shape      {34}
        \text       {Programmer B}
      \stopFLOWcell

      \startFLOWcell
        \location   {3,3}
        \name       {progC}
        \shape      {34}
        \text       {Programmer C}
      \stopFLOWcell

    \stopFLOWchart

    \FLOWchart[subversion]

    \stoptext

This does reasonably what I want. I just want one more thing. The three
figures on the middle line are part of subversion. I would like to show this
by putting a a dashed box around it. Is this possible?

-- 
Cecil Westerhof