Helpdesk restrict knowledge base to specific users or per HD Customer

Is this possible?

Also, how do you assign a user to a customer in the portal? I figured it can be done through Desk, but cannot find out how to do it in portal.

You want to assign knowledge base articles or tickets to specific users?
For KB restriction, maybe try user permissions?

is this working as expected @mincerray

Last year, it was not working. I haven’t had the chance to check recently if there were any improvements.