//ReadData("datasample.cds");in the FormLoad, then you will see the flat table set up by calling InitData. You can then right-click the left cell, and set its indent level to make this flat table look like a tree. The idea is that you can do the same thing from code as you create the CollapsibleDataSource.data. Once you have your table created, you can serialize it in the cds format so it then could be read from file from that point on. But the first cds structure either has to be done from code, or from the UI (rightclicking etc.). This sample does not use the standard AddNode/RemoveNode sturcture you might see in a treeview.