Hi
If you mean you have multiple playlists, I think you should be able to combine them into one smartlist, sure
But it depends on how you define duplicates. At the very least you should do Name+Artist I'd think (or some other criteria like genre)
My exact duplicate search includes Album Artist, Album, Track No., Name (track no is needed for some jazz alternate takes)
for your purposes, Artist+Album+Name should do it (or just Artist+Name if you want to avoid dupes from compilations albums) - you can use the "Remove duplicates" in the wizard or ~nodup=[Artist],[Name] if you are typing it in, add the playlist to combine.
I think its easier than to search for dupes ("Only Duplicates of") and then edit them out. But maybe some "versions" are better than others so I suppose you can do it whichever way suits best
hope this helps some