Restrict a user to a single Space only using Groups

[Simon Lai]

Hello, this is the scenario

User A has been added to Group FA

FA group has been assigned to Space FA.

I only want to restrict User A to be able to see Space FA and nothing else in Confluence.

I don't want to modify / change the access the rest of the users who currently are setup to have (to all spaces and pages except for those pages specifically with a permission on it).

Is there any way to easily do this?