Hi James,
In the TableDescriptor.GroupedColumns.Changed event, you can add your custom categorizer object to the SortColumnDescriptor. To create custom Categorizer objects, you define classes that implement ICategorizer. When you do this, whenever you group a specfic column it will be custom grouped.
Please refer this forum thread for a sample application
http://www.syncfusion.com/support/Forums/message.aspx?MessageID=57064Also, check this knowledgebase article that shows you "How to create custom group in a GridGroupingControl?".
http://www.syncfusion.com/support/kb/grid/Default.aspx?ToDo=view&questId=147Best regards,
Haneef