Flexible Sorting in Reports

In a report with multiple grouping levels, sort groupings by the summary value that defines each grouping.
Available in: All editions except Database.com

User Permissions Needed
To sort report results: “Run Reports”

For example, you’ve grouped an Opportunities report by type of business, in order to highlight the most promising deals. Each Type grouping is in turn grouped by Stage, and each Stage grouping is grouped by Lead Source. Now you can sort the Type grouping by Amount, the Stage grouping by Stage, and the Lead Source grouping by Record Count.

This includes both standard summary values and values that are generated by a custom summary formula.

Each grouping level can be sorted independently. Sorting a report by grouping