Using setTreeChooser in fillWmTemplateDescriptor for a service

We have been trying to provide the collection name and the doctypes inside it in a tree structure for a particular service in the tamino adapter.

sailing
|
|_yacht
|
|
ino:etc
|
|_image

this is the code sample we have used

d.setTreeChooser(new String[]{“collection”, “doctype”}, “.”); d.setResourceDomain(“collection”, “collectionNames”, null); d.setResourceDomain(“doctype”, “doctypeNames”, new String[]{“collection”});

And in the adapterResourceDomainLookup method we are returning values for collection names and the doctypes.

The tree is displayed only with the collection names like
+ino:etc
+sailing

How to get the doctype names inside the respective root nodes

Regards, Aravind