This is not supported. Out of the box the Grid provides binding/editing to a flat model and when creating hierarchy
each level of the hierarchy levels should explicitly declare its own dataSource and transport options. Each level of the hierarchy will perform its own request and fill its table with data.
However there is a workaround which you can use only to display (you wont be able to edit the hierarchy) structure of several level with your Grid.
To demonstrate how to achieve this I created a sample project.
You can use it as a base point and extend it with more and complex logic.
the Telerik team
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