Modelling.

@debayan1109'

1)The aggregation in this case will apply automatically if you create a separate module dimensioned only by Department.

2) You would need to create a module for mapping dimensioned by Employee with a line item Department.

Use LOOKUP function here https://help.anaplan.com/f8baa402-606d-4764-a349-d8003fa383be-LOOKUP

Salary[LOOKUP: Mapping module.Department]