There's no way to have different domains (e.g. po, po-properties) in different categories
Submitted by Gil Forcada
Currently with the proposal on #680843 there's a wish to have gtk+ po domain in a category but have gtk+ po-properties domain in another one.
Right now the branches edit form does not allow that (and also the listing displays).
One possible implementation would be to split the branches edit form to have a form for each domain.