Something like review groups but per-item, where multiple tags can be set per-item.

Another way would be searching based on arbitrary metadata keys which could be managed by users i.e. searching for all items with metadata key/values of user and asset, or asset and department would help you track progression.

At the moment the review groups are helpful but you only can 'tag' a review with one group, so reviews with multiple types of submissions in them can hide submissions if the review can only be tagged with one group.

For instance if you had a daily review playlist that had animation, lighting, and comp submissions in it, there is not a way to later find all comp submissions in a project. You only can tag the playlist as a whole.

The benefit of doing it per-item is that you could get back a list of items to compare (i.e. does mickey's sequence 005,shot 004 animation look better then last weeks?), although that would require the ability to compare and a/b across playlists.

At the moment organizing everything based on one level (the playlist) is a bit restrictive so any way to open that up for either hierarchical or set based organization would be great.