Authorization for cost center report for department

Dear SAP experts,

We have a requirement that for cost center report S_ALR_87013611, a user should be able to view the balances of cost centers belonging to his department.

For S_ALR_87013611, an authorization object, K_REPO_CCA is available which has cost center group. However for this authorization object, user is assigned higher cost center group i.e. cost center group of plant rather than department.

Hence do we need to create a separate role for each department ? or is there any alternative way. However this would require us to create so many roles as there are many plants and many departments.

Thanks and Regards

Chetan.