The student roster is shared across all tabs in the same gradebook.
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 gradebook view, tap and 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 Hide
Show a hidden student
Tap on tools (top bar) / Students
Here you may either select a group of students, and tap Unhide
or you can directly tap on the eye icon next to each hidden student.
