How to filter by Group?

I would like to filter by Group but don't see it in the Filters flyout nor do I see a sortcut in the searchbar.

I need something at a higher level than project. I use Group like I use 'Client' ... so I've got a team of developers working on AAA's projects and another team of developers working on BBB's projects and I need to see all issues associated with AAA's projects (where AAA and BBB are two different companies).

Am I just missing it - or is there a better way?

Thanks,

-Luther