Can you sort on a Group sum?

[CelSal01]

I have a Billing Record report that I want to sort by project total billed amount (highest to lowest). There may be more than one billing record per project. I have the report grouped by Project Reference number and showing a sum of the amounts. The report is currently sorting in descending order on the Billing Record amount. The attached screenshot shows the group sums but it's not in descending order. Is there a way to sort by the group sum? 

[Sven-iX · Accepted solution]

I don't think it's possible because the group sum is a dynamically evaluated number per each group - and a sort only affects the individual rows. 

An alternate route might be to do a project report where you use one of these fields (in your case I think it's Actual billable expense cost) and link to the project's billingRecords page?

These fields are also aggregates values but it's an actual value on the project so you would be able to sort on it.