I have a complicated organization diagram / process heirarchy map. I would like to be able, with a modified mouse click, to automatically select all boxes downstream from the box I click on. Thus i could color all at once, for example, a specific path choice from many choices possible.

Selecting the items this way in Outline View ALMOST works, but it should show all the items selected with their own selection handles, not as a group.

The diagram has 7 levels; beyond the 2nd level, the path choices overlap (one box leads to several, or several boxes lead to one) and sometimes skip levels (e.g., one of the 3rd level boxes leads directly to a level 7 destination).