Post: #2

It depends on what you are wanting to do with them...

The easiest way to see them ingame without scripting anything would be in debug mode. Simple do .info or .xshow.multiregion and target the gembit that is the multi (not the doors or sign) it will be named the same as the buiding.
Alternatively if you feel like a little light scripting you could create a simple function that will output link.multiregion, then you could simply target the sign, door e.t.c.. to see how big the multi is.

n.b. The output will always be 4 numbers like:

-4, 3, 3, 4

This relates to the number of tiles the multi extends from the center point (gembit) in each direction.