Playlists within playlists are a basic feature the empeg has.

What you have to realize, though, is that one songs are selected to be played, there are no longer any playlists involved. It flattens everything out into one big list of tracks in memory and no longer references or even knows about the playlists you selected them from once you've selected them.

IMO, it's the one big flaw of the empeg player's software. There are any number of times that I'd like to have the concept of playing playlists within the running order, and this is just one of them.