I've gone into Roles and just used it by username, removed the groups from the project and doing roles strictly by username. As a user, they cannot select a project from the drop down at the top of JIRA studio. So I've successfully hidden items, but I don't want those projects showing up in the activity stream.
For instance:
User 1 is working on Project X
User 2 is working on Project Y
User 1 can see Project X & Y in activity Stream.... they should only see Project X.
Any suggestions?