Check out Settings > [Server Name] > Manage > Libraries to configure which hubs/recommendations of a library should show on the library Recommended tab or the home page itself.
https://support.plex.tv/articles/manage-recommendations/
You can even publish your own collections (incl. smart collections based on your own definition).
https://support.plex.tv/articles/publishing-collections/
There’s an existing feature suggestion discussing an option to get recommendations based on what you’ve watched / liked. For that scope I suggest you comment/vote in that thread in order to avoid distracting or cannibalizing votes.
