You should be able to filter which photos are NOT in a folder or album in Lightroom CC
I am trying to organize my photos in Lightroom CC, which has proven challenging. One extreme difficulty is that once I add a photo to an album in a folder, it remains in the same list of "My Photos". There is no way for me to see which photos have NOT been sorted. With this being the cloud based solution that should keep things consistent, I hope this can get fixed. This isn't a problem with say, Google Photos.