This feature is only available to Q&A admins and Q&A observers with full control.
When disclosing an Answer you have 2 options, back to the team the question came from and to all room users.
You will see this option
By default it will be selected to go to Question Authors team, so none of the other external teams will see this Question and Answer. This is the most likely method people will adopt.
If selecting all data room people this lets all the Guests see the selected Question and Answer in their Q&A list, but the identity of the author of either the question or the answer will be hidden. However, any member of the author's Team can see their full name and email address. This is what Guests could see when the Q&A is raised by another team and disclosed to them:
💡Tip: If their Team security settings have been denied access to a Subject they will not be able to see this question and answer.