Sort by "Creator" and "Not Signed"

Is possible to search through your collection by creator and for unsigned books? Getting ready for con season and I’d like to be able to look at which books I have unsigned by specific creators.

I’m able to filter “Signed by” and “Creator” but not by “Not Signed” and “Creator”. When going into the “Not Signed” filter there is no option to sort by creator.
I’m assuming this is possible and I’m just not figuring it out. Does anyone know how to do this?

I just replied to your email as well.

You can tap the folder icon top left, then “Add new favorite”

Then add the fields:
Signed
All Creators

(in that order)
You can then tap “no” and then tap a creator. But this will only work for books that are not signed at all. And from your email I gathered you’re looking for a way where a book is made by 3 creators, signed by 2 of them, so you can find out “the missing signature” - and that is not possible in our app (I can’t think of a workaround).