Thank you for the answer!
Yes, in the past days I got to something similar solution. But it doesn't help, as I use Jomsocial on the sites and doesn't matter a user is present on a site or not, he will be seen by others in Jomsocial as Jomsocial doesn't have the partial sharing.
If my user registers on a slave site, but he is set not to be present on the master, he cannot login the master, but any other master users can see his profile in Jomsocial.
I want if a user shares photos in Jomsocial with registered user only than only his slave site registered users should see his photos not the master site regsitered user. But this seems not to be possible.
So, as partial user sharing is only for Joomla users I think I bought the component unnecessarily
