Hi Maqsood,
Thanks for your interest in Syncfusion Products.
Toggling between flat and hierarchical table with the same datasource object can be achieved by resetting the setting and resetting hiererchy levels and rebinding the datasource.
Please refer to the sample in the following link in which this has been achieved.
http://help.syncfusion.com/support/samples/Grid.Windows/6.3.0.30/F91920.zipRegards,
Rajadurai