Thank you for your question.
Unfortunately, putting Docking in another Docking control is not a supported feature. There is a PITS item, which you can view here
. You can vote for it, track its status and see when it is going to be implemented.
If you have any other questions about our controls please let us know.
the Telerik team
Do you want to have your say when we set our development plans? Do you want to know when a feature you care about is added or when a bug fixed? Explore the Telerik Public Issue Tracking
system and vote to affect the priority of the items.