you've grouped your tracks together and like a good citizen you're compressing the bus to keep the dynamics under control. but then for one reason or another you need to ungroup the tracks; maybe you want to group your group with other groups, maybe you want to split the grouping. but as soon as you degroup this group, however, you'll lose the bus compression! the whole point of compressing a group of signals is to have the sum total influence the dynamics of each other so you can't simply place a the same compressor on every track. and printing the sub-mix isn't always an option when you plan to change things later. it's usually at this point you get all in a fuss. well, no longer:

here's where we're at: we've got a group of tracks and we like the way they sound with the compressor. we'd like to keep the sound the same but you also want to ungroup.