It is not possible to suppress the detail grid grouping from the GroupByRow itself. You can remove the title of the DetailGrid from the GroupByRow by setting the DetailGridTemplate.Title to an empty string.
To prevent the user from grouping columns from the detail girds, you need to set the CanBeGrouped property to false on each Column that pertains to the detail grid.
Imported from legacy forums. Posted by André (had 361 views)