Currently we don’t have option to achieve this feature in our existing PivotGrid widget (Desktop Designer).
We would like to inform you that, with v3.2 release, we slowed down new developments in the Desktop Designer since we introduced Web-based Dashboard Designer integrated with Dashboard Server in the same release. Our further active developments will be in the new web-based Dashboard Designer. We are currently working to equalize its feature set with the desktop designer for easy migration.
Regarding this feature request, it is in our current year road map already and it will be available in any of our upcoming releases in web designer with PivotGrid widget integrated.
We appreciate your patience.