Note: This test requires Conditional activities to be enabled, and a course with one teacher and two students, A and B. Group mode must be set in the course.
1) As a teacher, create two groups, A and B and, add Student A to group A and Student B to group B.
2) Set up a lesson, with Common module settings as Groups, visible or separate, and in Restrict access, choose Groups and then "Student must match.... Group A".
3) Click the 'eye" icon to hide the restriction completely.
4) Log in as Student B and verify you do not see the lesson at all.
5) Log in as Student A and verify you can access the lesson.