It's hard to say without knowing more about your database design. If this is all in one table and you've defined the balance as a summary field, you can add a sub summary part sorted by a field such as an Employee ID field that groups the records by employee. You can put your summary fields in this sub summary part and see the subtotals for each employee.
Here's a tutorial on summary reports that may help: Creating Filemaker Pro summary reports--Tutorial
This tutorial shows how to combine info from two related tables in one summary report--which may not be a needed feature of your report, but it also shows in detail how to add sub summary parts to your layout.