Budgets Report

Budgets Report

When running the budget progress report I cannot drill down into the figures to find out where they have come from.
If a budget has gone over then the budget managers would need to analyse where the spend has come from. 
I have managed to add a couple of reports. One for PO's and one for invoices but I cannot match to the exact figure on the budget progress report?
It would be really helpful to be able to drill down into these figures.