Proof/Project View Combo

[SamanthaIsin]

I'm looking to create a view for one of our art directors so he can see what projects have proofs and what don't. The only existing filter I can find that would do this is Project >> Has Documents. I'm looking for a way to say Project >> Has Proofs or Has documents that are proofs.

Suggestions? Refer to the image below to see what we currently have set up.

[AnthonyIm]

Interesting challenge... the issue is that the Proof ID is on the document version, not the document. So to have it be a collection in a collection and I'm not sure how to do that.