I love having the ability to group some of my tabs but I'm wondering if it's possible to create "subgroups" of tabs inside of a "group". For instance, it would be very confusing & even chaotic to have one tab group named "Computers" that has tabs for sites where I buy computers/parts/software, sites where I go to for support for my hardware/software issues, & sites where where I can read reviews about the up & coming new hardware/software. However, the chaos would go away if I could have 3 tab subgroups (Shopping, Support, & News) UNDER a "top level" tab named "Computers".

From what I've been able to find on the Firefox website, this capability is not yet available but I'm wondering if it's something that's currently in development. If not, I would like to suggest that it be seriously considered. I realize that some people could take this kind of capability to the extreme, with hundreds of tabs organized using multiple "sub-tiers" & trying to develop something to support the extreme cases would be a nightmare. However, the ability to even two levels (groups & 1 level of subgroups) would be a HUGE improvement over the current situation.