While using Accordion component with creationPolicy="all", tree components which are placed in accordion's different panels, will not expanded at creationcomplete.
Trees are created perfectly but not expand its level at initial creationComplete time.
If I placed tree in regular panel and executed, tree levels are perfectly expaned.
Expand level code is called at creationComplete of Tree.
i got my mistake.
I am using callLater(). Now its working perfect.