I make what I call the Recycler IPA from time to time, it's a lot of fun to do and it goes something like this:
10 gallon mash tun full to the top, use the first runnings to brew a 5 gallon big double IPA, collect the second runnings for the Recycler IPA for a second boil. The double IPA has a ton of late whole leaf hops, including 6 oz at zero. Now I love wasting hops as much as most hop heads but I got to thinking I would use those late hops to bitter the second runnings beer. After chilling and transferring there's a bunch of hop cones left in the boil kettle. Take a guess and how many AA's you are looking at, consider how many you want for the Recycler boil, then scoop out a bunch and discard. In my case I typically leave about 40% in the kettle to be the first wort hops for the second beer. Proceed with whatever hop schedule you have in mind for the smaller beer.
Now you have a big and a little IPA fermenting side by side. I like to cold crash both beers and keg them at the same time, then let them warm up for a day before dry hopping. I dry hop in a keg with an irresponsible amount of whole cone hops in a mesh bag. I dry hop the double first with a closed transfer by running a jumper over to the dry hop keg for a few days, then right back to the serving keg, chill, carb and enjoy. Same procedure for the Recycler beer, only using the same dry hops for a second time. I have found that I get an amazing amount of aroma, even with the second use, and it kind of works to scale when you go from the big beer to the little one.
Now I suppose you could recover those dry hops and use them to bitter another beer, but as tomsawyer said, bittering hops are cheap.