Hi,
I’m very sorry, I’m not sure what’s wrong with your other ticket, I am not able to open it, and I didn’t even get a notification – something might have happened with the database, I will take care of that later.
For your issue, make sure to read this documentaion first. Basically you want to set the settings visiblity and layout to block here.
To restrict all results to a specific category, check this documentation, it should explain everything.