Question: I'd like to hide my other accounts on a single Stack Exchange site, but not all of them. I found the "hide communities" section, but when I go there on the site I'd like to be more private and remove communities, it appears to hide them on all my accounts.

Is it possible to hide communities on a single site, but leave them publicly visible everywhere else?

Answer: 
No, you cannot

Once you hide it from 

**<https://askubuntu.com/users/hidecommunities/current>** say, it will be reflected directly in 

**<https://meta.stackoverflow.com/users/hidecommunities/current>**

The websites are interlinked and changing in one instantly reflects in other ones.
Hiding community(es) on the single site is not possible and useless.

If the community is not hidden anybody can access you [network profile](https://stackexchange.com/users/295527/bijendra?tab=accounts) via corresponding link in the currect community profile section.

Network profile contains a link of all your publicly visible accounts. So if hiding a community on the single site was possible it's unclear what should be displayed in such list. Hence it's not allowed.