Besides the trivial tabular data visualization, the RadGridView is capable of displaying hierarchical data in the form of nested tables. In the Basic Hierarchies topic you can find information about the basics of building a hierarchical grid.
Figure 1: Basic Hierarchies
The RadGridView also allows you to create hierarchies in your grid based on some custom logic. In that case you can benefit from the RowDetails options. To learn more about these take a look at the Row Details topic.
Figure 2: Row Details
In the cases when the nested grids should display data of the same type as the master grid, you can build a self-referencing grid. To learn more about the self-referencing approach take a look at the Self-Referencing GridView topic.
Figure 3: Self-Referencing GridView
Please bear in mind that the DataContext of the row details presenter and the hierarchy child presenter is the parent row and not the context of the RadGridView itself. You can change the DataContext either in the LoadingRowDetails event when dealing with row details or in the DataLoding event when building a hierarchy with table definitions.