Let's say someone explains you something. But it's not clear where (s)he's getting at, or what's the point. Then at some point you can say, "And the point being... what exactly?"
Now, let's say someone wants you to send him/her a parcel. (S)he tells everything save for the address. Can I ask, "And the address being?.." I guess I can't, but why? If I can, then again, why? Also I guess sentences that start with "Meaning, ..." are somehow relevant here.