How show 3 vertical file displays in DO 10 Pro

Is there any way to show 3 vertical file displays (plus a folder tree to the left) in DO 10 Pro ? I want to show all 3 of my drive partitions at the same time. Please explain how, if it's possible!

Only by using two windows. One window can show at most two file displays side-by-side (plus the folder tree, folder tabs etc.)

Personally I think that using dual and single has no sense. Operations works only inside dual (like copy etc). Better option will be open 3 independent single windows - every of them with folder tree. Then all operations will be possible from any window to other one. I've check - it looks nice, but I don't know is possible to open set of that listers easy way.

It's easy using layouts.

Exactly how can I use layouts to show 3 vertical file displays??

Open two or three windows, then use Settings > Lister Layouts to save them as a layout. You can then reopen them via the same menu or various other methods.