Hi Alejandro,
Please refer to the forum thread below that has a sample, which supports drag and drop opeartion for grouped columns.
http://www.syncfusion.com/Support/forums/message.aspx?MessageID=40606Take a look into the sample below that supports drag and drop for nested tables in GGC.
http://www.syncfusion.com/support/user/uploads/DragDrop_GGC0.zipLet us know if you need any further assistance.
Thanks,
Rajagopal