Hi,
By default it is not possible to have different child tables of parent rows. One thing you could achieve the desired behavior by establishing multiple relations from parent to child and hide the unnecssary tables from the parent row.
The ChildTable can be made hidden when it has no records to show up, by using a CustomEngine. Also you need to handle QueryCellStyleInfo event of the GridGroupiingControl to hide the +/- sign. Please refer the following KB article that shows how to hide the ChildTable that doesn't have any records to show up in GridGroupingControl.
KB link:
http://www.syncfusion.com/support/kb/721/How-to-hide-the-ChildTable-that-doesnPlease use the following link for the sample:
http://help.syncfusion.com/samples/kb/grid.windows/GGCHideEmptyChildTable/main.htmRegards,
Jisha