Now, you might say, he's switching from FF, we do things differently. OK, I'm willing to listen to that.

I have found two options so far: The top bar. Err.. yeah, FF has that, too, for half a dozen of your most used bm But for searching for 1 of a myriad of bm in 3, maybe 4 levels of sub-directories this ain't cutting it.
The on-demand window. OK, so I can open a bm tab, which gives me a sidebar plus the larger part of the tab shows the bm in the folder selected on the left. What a waste, and not permanent. I would always have to reselect Ctrl+Shift+B to show that tab again.

Any other options? Thanks for reading.