IIRC, once the empeg is playing a list of files it has no knowledge where they came from, therefore the concept of a 'next playlist' isn't valid (what is the next playlist if you're playing the result of a search, or the entire content of the player?)
The closest thing to this is to manually go into the playlist menu and then hold the bottom button; this will warp you to where you last made a select in the playlist hierarchy, allow you to move to the 'next' list manually.
/Michael
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/Michael