1. Create project.
2. Add Tree to the page. One node will be added by default with id "treeNode1".
3. Add new node to tree root and set id "treeNode2".
4. Add new node to previously added node and set id "treeNode3".
5. Add somewhere (for example in prerender() method) code like:

System.out.println("treeNode1=" + tree1.findComponent("treeNode1"));
System.out.println("treeNode2=" + tree1.findComponent("treeNode2"));
System.out.println("treeNode3=" + tree1.findComponent("treeNode3"));
System.out.println("treeNode2->treeNode3=" +
tree1.findComponent("treeNode2").findComponent("treeNode3"));

6. Run project.

Result: In output we get something like:
treeNode1=com.sun.rave.web.ui.component.TreeNode@6ba2ed
treeNode2=com.sun.rave.web.ui.component.TreeNode@8sdfl4
treeNode3=null
treeNode2->treeNode3=com.sun.rave.web.ui.component.TreeNode@4sdt0s

So, for tree we can find only components with level 1, we can't find components
with level 2 or higher. If we want to get components with level 2, we must
serach it in components with level 1; components with level 3, we must serach it
in components with level 2 and so on.
But if I want to find any component in tree, I want to search through whole
tree, not only through components with level 1.