Nested properties are not supported out of the box. Nevertheless, this functionality can be easily achieved by inheriting DataGridTextColumn.
I have prepared sample project demonstrating how this can be achieved. Please have a look at the attachment and let me know if this helps.
P.S. Keep in mind that nested properties are not supported in Edit scenario (if you have such scenario you can set CanUserEdit to this column to be displayed in read-only mode always).
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?
Telerik Feedback Portal
and vote to affect the priority of the items