A tutor will be able to see all learners for the groups they are assigned to if they have the “Tutor Console – View all in assigned groups” permission.

They can filter between “All Learners”, “My Learners” and "Secondary Learners" using the filters available in the Tutor Console.

To restrict the learners that a tutor can see, you can remove them from any groups that they don’t require access to.