in iTunes, I make a Smart Playlist

File --> New Smart Playlist

I sort through different levels using these criteria

Album: PopUp Chinese

Artist: Absolute Beginners (or Elementary, or Intermediate, etc.)

I name the Smart Playlist with the name of the level (Elementary, Intermediate)

When I want just the dialogue or the fix, I add

Name - contains - dialogue (or fix)

When I want to exclude the dialogue and the fix

Name - doesn't contain - dialogue (or fix)

In the podcast stream, all the episodes are lumped together

the levels (elementary, etc.) don't show up until I play an episode or add them to the playlist