There’s an existing feature suggestion discussing an option to hide content you’re not interested in from a shared server (though as MovieFan.Plex pointed out, that’s rather a long shot). I suggest you comment/vote in that thread in order to avoid distracting or cannibalizing votes (in case you’re interested anyway; if so we’ll close this thread as a duplicate).
An alternative could be to ask your friend to apply a sharing label and limit their shares with you to that label… this way you’ll only get to see that. Keep in mind such custom library access restrictions require a Plex Pass membership of the person who’s sharing.
https://support.plex.tv/articles/204232573-restricting-the-shares/
