There are now two sections on the Registration tab. The “Paratext Repositories” section lists PT project files that share the same project registration, including Auxiliary projects, or BackTranslation and Transliteration (though these can in rare cases have separate registrations).
The second section, “Related Projects”, lists separate project registrations that are connected via parent-child relationship. This can include Daughter or StudyBible projects, and in some cases Transliteration and BackTranslation (if they are registered separately). It’s bidirectional so the parent shows up on the page of the child and vice versa. I can probably improve this view further by adding information about why they are connected.
If you are seeing projects listed that don’t appear to be connected please email me a link to the project and I’ll take a look.