In this example, we demonstrated two general approaches to achieve this goal:1. If the data source object does not have a property that includes all child rows, you can handle changes of the master grid's selection and filter the detail grid's source based on the selected value. In the latest version of this example, we implemented this logic in the CurrentRow property setter; this property is bound to the GridControl's CurrentItem property.
2. In the case when master row objects contain child items (in our example, GridControl contains DataRowView objects with a separate CompanyModels property), it's easier to bind the detail grid's ItemsSource property to the selected item directly.