alt Hacker NewsI'm not sure if this is what you want but you can set two lists of tags for each user that works as items blacklists and whitelists. Then you tag whatever media you want with those and they will appear or disappear for that user.
You can find this feature in the admin control panel -> Users -> select an user -> Parental control (tab)
There is also an Access tab, together both can be used to lock things down fairly well.
I didn't know about tags nor their uses in Parental Control, thanks!
And after checking it out, if you use Sonarr/Radarr for managing your media, the tags you put there are synced to Jellyfin, so that's even better.