V11 Dual Directory Tree

How can I view Dual Directory Trees in v11 when I have two (2) Listers showing? I have tried to select dual horizontal directory trees in preferences, but nothing changes. I still only get one tree.

Turn on Preferences / Folder Tree / Options / Open second Folder Tree in dual display mode.

I'd like to open a second folder tree just one time in dual display mode, but not change the preferences so that it happens all the time. Thank you.

In the Lister menu, select Dual Folder Tree, or press Shift + F8.

Oh, oh... I actually have Directory Opus, and there is no such menu item (that I can find), and Shift+F8 does nothing.

In Opus 10 the command wasn't in the default menus but you can add it yourself. The command to use is:

Set TREE=Toggle,Right