Is it possible to use the Group and Outline tool in Calc to create groups of non-contiguous (i.e. not adjacent) rows/columns?
I’m trying to create a collapsible tree. (I wanted to upload a diagram of what I’m trying to do but the site won’t let me, so I’ll just have to demonstrate with text.) 
The plan is to make the column represented by A into one group, then the B’s into another group, then the C’s into a third group, and so on, so that it can collapse in the manner demonstrated below. Is there a way I can do this? (Or is there a better system for creating collapsible trees like this in Calc that anyone can teach me?)
D|C|DD|B|DD|C|DD|C|DD|A|DD|C|DD|C|DD|B|DD|C|D →
C|B|CC|A|CC|B|C →
B|A|B →
A
Again, sorry for the bizarrely abstract visual representation, but I only just registered here to ask this question and apparently I can’t post images (which would have been much more useful) yet.