In case a student is transferred to another class you may want to hide that
student from a specific tab.
Hiding a single student
From the grade book view, tap&hold on a student and Hide
The students filter (top bar) will let you focus on a selection of students without having to hide them first. More details explained here
Hide a group of students
Tap on tools (top bar) / Students / Select your students and HideUn-hide a student
Tap on tools (top bar) / StudentsHere you may either select a group of students, and tap on unhide
or you can directly tap on the eye icon next to each hidden student.