P: Have more than one target collection simultaneously

Another request is to be able to have a few more target collections exist simultaneously.  For example, I would like to go through folders of photos and press the “B” key to send some photos to one collection, and then press a different key to send photos to a different collection.  This would save me from having to go through a folder of photos two times.  And if I could have 3 target collections simultaneously, that could save me from having to go through a folder of photos 3 times. And etc.

Thanks