If I have my tree organized the following way for example
joint
-broker 1 (more buy & hold)
-broker 2 (more of a trading portfolio)
me
-ira r/o (broker 1)
-ira r/o (broker 2)
-ira roth (broker 1)
-...
wife
-ira r/o (broker 1)
-ira r/o (broker 2)
-ira roth
I sometime would also like to look at returns by turnover characteristics or expenses. I can copy and paste the sub-portfolios so that I have another tree
buy & hold port
-JT broker1
-me ira r/o broker 1
-...
trading port
-JT broker 2
-...
But the problem with that approach seems to be if a new investment gets added to a sub-portfolio, it will not be reflected in its copy, so I would need to delete the second set of trees and re-copy, and at my age late at night or after three martinis, I could just as easily delete the original sub-portfolio. Then I would need to restore from backup and figure out what changed since then etc.
If you can make FM traversing down one tree, I am sure you can make it traversing down multiple trees.

Bob