While I am able to hide stereotypes or individual objects, the "hide unlinked" command does not seem to work currently
To answer to a very old question, from V1.2020.6 (5 Apr, 2020) and:
We can now use 'hide' or 'remove' '@unlinked':
(C) -> [D]
See also similar old request here:
Then the documentation is also updated:
If that can help,Regards,Th.