How to show/hide a few topics n RoboHelp 2022 without generating two separate responsive HTML output

Are you saying that you want access to the help to be determined by a property on a user login record in the application?

I don't think you really can do this easily.

I can think of a couple of things but they have drawbacks.

You could use dynamic content filtering. https://www.grainge.org/RoboHelp_Tour/rh2022/outputs/dynamic_content.htm

By default users choose their own filters, but the developer, they could add the correct filter expression to the URL based on the user login property (assuming this is what you mean by role) so the users sees the appropriate help. If you didn't want the user to be able to change this through the skin, you could hide the Filters panel. I think in Responsive it's a toggle, and Frameless you delete the applicable topic page button? But I don't have RH2022 to check right now.

However, if the user manually removes the filter part of the url I think they can then see the full help. It's possible not many people would try this, but you'd need to determine whether this is a problem in your scenario.

Another option is tagging the topics but not specifying those conditions in the build expression. The condition tags go through to the output. Your developers could then apply a display: none; to content with data-condition that includes the condition tag that shouldn't be seen. However that only applies to content, not the TOC or search etc as far as I know. Perhaps the developers could look at the existing output code, and figure out how to exclude the topics from TOC, search etc and you could include some custom code in the User Assets section of the skin.  

And if users inspects the output code, I believe they would be able to see that content. Again, you'll have to determine if this is a problem in your situation.

Anyway, that's a couple of options to at least investigate.