I would like to ask help on how to change the field 'Branch' seen from the New Schedule Form from single selection to multiple selection (like the first field 'Employee').
I actually have managed to figure out how to turn it into multiple selection in the UI but I'm having problems on successfully saving multiple records at the same time, like the current mass adding to the schedule, if multiple employees are selected.
What I'm actually planning was if multiple employees are selected and also multiple branches, if I click save it should have multiple rows shown in the schedule grid per employee per branch.
Can someone guide me which codes to edit in ScheduleViewController.js, where I believe the changes have to be done? I tried looking for occurences of
"user_id, user_ids, branch_id, branch_ids"
but the codes really looks complicated to me

I tried to look at other forms if there is a multiple selection field used for Branch but there is nothing I've found.
I hope my request is reasonable. Thanks
Btw, im using community edition, see below