Hi Kasey,
Thank you for posting query to us.
Please refer this sample which shows how to bind the subproperty in GridDataBoundGrid.
http://websamples.syncfusion.com/samples/Grid.Windows/F67349GDBG/main.htmThe column titled "Address Workaround" uses C# code to access the sub-property. If you would like to set MappingName to "Payee.Address" to bind to the Address property of the Payee property of an Entry "row object". Then you will let the CellValue return the "row object", and you can use the DisplayMember to point to a property in this 'row object'. (If you set the GridStyleInfo.ShowButtons property to GridShowButtons.Hide, then you would not know the cell was a combobox.)
gridDataBoundGrid1.Binder.InternalColumns[0].StyleInfo.ShowButtons = Syncfusion.Windows.Forms.Grid.GridShowButtons.Hide;
Thank you for using Syncfusion Products.
Best Regards,
Jeba.