If you are on the Chart of Accounts page, you will first need to add the Budgeted Amount (or the Budgeted Credit Amount / Budgeted Debit Amount) to the page. You'll need to do it from the Development Environment, so a developer will be needed. Setting a filter on Budget code will not change the values displayed in the Net Change and Balance fields. These are reserved for actuals.
Also, in addition to setting the Budget Filter, I suggest you also set the Date Filter in the 'Limit Totals To' filter area.
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