Hi Yana,
With regards to Manual Layout in Essential Diagram, currently we have support to specifying only the Collection of Nodes in ItemSource property but not for LineConnectors. When a Hierarchical data with HierarchicalDataTemplate is used, a Parent node will be connected to its children using LineConnector, which is presented in Business Object Databinding sample. We have considered your requirement as a feature request and We will implement this in any of our future releases.
If you would like us to notify about the feature implementation then, you may create a Direct-Trac using our Direct-Trac Support system.
Here is the link, please login into
http://www.syncfusion.com/Account/ and we will be happy to help you.
Please let us know if you have any further concerns
Regards,
Ramya