If I want to bind a WebDataMenu (or UltraWebMenu) to an XmlDataSource, how do I indicate a separator in the XML file?

For example, in the documentation example

http://help.infragistics.com/NetAdvantage/ASPNET/2010.1/CLR3.5/?page=WebDataMenu_Binding_WebDataMenu_to_an_Xml_Data_Source.html

how would that example indicate a separator?

If it can't be done with an XML data source, which kind of data source would support indicating a separator?

Thanks.