Understanding groups and permissions

When I go to create a group, one of the bullets states:

Members of a group may only view projects they have permission to access

How do I do that? It looks like if the user is a member of a group, they have access to all the projects in that group. I would like to assign a given user elevated privileges to a project, but have that project in a group.

@end_user

Go to http://<GITLAB_EXTERNAL_URL>/<GROUPNAME>/<PROJECTNAME>/project_members

From the content window, you can add new users to the project with custom roles under the Add new user to project