This feature request has been submitted on github too.

Scenario: OST serves for whole portfolio of services and we will push users to use web and Help Topics (because of custom forms). Some Help Topics (and their forms) can tell too much about some provided service (which is not public) to other customers. So we need to prevent every registered User to know/select/use every possible Topic in the system but let some Users/Companies to use them.

Idea: Admin can set several Help Topics as Private and Agent can choose this particular Topic (one by one or just parent one) just for specific Company.

Note: additional change of the Topic by Agent or Ticket Filters is not a solution because custom forms doesn't show up in the ticket then and so User can't fill required data (yes, User technically can write everything in the long description but this is not what we need, they generally must be guided by forms).