Is it possible to create categories within the Invoice list view?  Essentially, I would like to have 2 folders just to add some organization. Each folder would contain the same items, but one would be the retail price and one would be the wholesale price.  It's not essential, but would really help create some organization within our list of items. 

Right now, I just sort the list... Is this the best way to do it?

Thanks,

Tegan