[ASalazarMX]

Sidebery does let you group tabs. Select a few from the sidebar, right click, group, give the group a name, and optionally, collapse so it doesn't take space.

Somehow it glitches and some groups can become undone, but fortunately I haven't seen that glitch in the last few months, it might be solved for good.

[jazzyjackson]

Thanks for pointing this out, just noticed I can move selected tabs to a new panel too, excellent.

I'll add that collapsed groups can be nested.