如何将子实体详细信息字段绑定到文本框？

My RadGridView is bound to child records via the parent entity's navigation property. Users can edit records in the grid. Now I'd like to also allow editing of child records outside of the grid. After selecting a record in the grid you could edit it using text boxes. I can't seem to find the right binding statement for each text box. My working child grid XAML looks something like this:My RadGridView is bound to child records via th