The System.Web.UI.IHierarchicalDataSource interface, like the System.Web.UI.IDataSource interface, defines a method that hierarchical data source controls use to retrieve a data source view. Like all System.Web.UI.DataSourceView helper objects that are associated with data source controls, a System.Web.UI.HierarchicalDataSourceView object defines the operations that the data source can perform with the underlying data. However, although data source controls that represent tabular data typically have only one named view, hierarchical data source controls support a view for each level of hierarchical data that the data source control represents. The level of hierarchical data is identified by a unique hierarchical path, passed as the viewPath parameter.