When custom groups are created in the Admissions Manager module or Pupil Manager they can be created as private to the user or shared (with or without editing abilities) with other users.
The Student Registers module allows you to search by custom group. However, only shared custom groups are listed. This forces users to share their own groups within the system, even if they have no value to other users. This is particularly problematic if the group in question deals with sensitive matters.
It would be great if the Student Registers module, in line with other modules, had the ability to list personal/private custom groups for the logged on user.