Calculate From Area - Materials List Tool Problem

[BoscoM]

I was trying to use this feature on a small detached deck which is part of an overall plan. So I use the tool, draw a rectangle around the deck and up pops a Materials List except that all it shows are ALL the landscape plants for the entire plan! It works correctly for Calculate from All Floors. CA 6 (16.3).

 

It's not a big deal since I really don't use the materials list that much -- more as a check than anything.