nPlosion by more than one field

We are using project costing and are adapting a report which takes budget information from that module. To move to project costing, we need the report to show an nPloded row, first showing the account code, then showing the analysis type underneath. I can easily nPlode by account code, but am not sure how to nPlode first by account and then by analysis type (BUD and CBU are analysis types). Can anyone suggest a solution here? Example attached. Thanks for your help with this.