It looks like your picture didn't make it through. Could you try posting it again?
Also, groups exist on geometry, not between different objects, if that's what you were referring to. Is it that you'd like to be able to be at an object level in the viewport and still select groups within single objects with the group list? That could become prohibitively memory- and time-intensive in large scenes with thousands of objects that each have a lot of groups, but it might be possible to have an option, (though I don't know the group list code). It will definitely have to dive into an object upon selecting a group in it, though, because I'm pretty sure selections depend on it.
There may be something qualitatively similar to object groups as well, if that's what you meant, but I'm not as familiar with objects, myself.