Thank you for contacting us.
The RadTreeView control does not support grouping. Nevertheless, you can go through all available hierarchies it supports in the online documentation. I think that the best way to achieve the desired scenario is to create a data source which defines self-referencing hierarchy. You can read more on the topic here.
Do not hesitate to write us back if you have further questions or issues.
the Telerik team
Explore the entire Telerik portfolio by downloading the Ultimate Collection trial package. Get now >>