Teachers are able to view any student's profile that has been assigned to them (Assigning Students to a Teacher) or if they have a lesson scheduled with them. This includes the recent and upcoming lesson sections, which will display the 10 most recent completed lessons and 5 upcoming lessons the student has, regardless of the teacher assigned to the lessons.
This is useful if you have substitute teachers that need to cover a class and view lesson notes to see a student's current progress.
However, in some cases you may want to limit the lessons that appear on a student's profile to only display lessons of the teacher viewing it. You can limit the recent and upcoming lessons sections by following these steps:
Click on "Account" and then click on "Account Settings".
Click on the "Users & Security" tab.
Scroll down to the Employee Accounts section.
Use the Toggle to turn the "Limit Student Recent & Upcoming Lessons" setting "On".
Save the form.