It's been several years since I've used it, so I could be completely wrong, but yes, I believe that kind of filtering only works at the catalog level, so all of

It's been several years since I've used it, so I could be completely wrong, but yes, I believe that kind of filtering only works at the catalog level, so all of your photos would have to be in the same catalog to gain that benefit. When I used it, I only had one catalog that encompassed my entire photo library. My impression is that Lightroom is really designed for you to go "all in" and let it organize everything.