How to apply Tree Layout

I was applied the tree layout to the diagram.And the node are connected in the reverse direction
Actual OutPut:

Expected Out Put:

By default GoJS thinks trees are composed of nodes connected by links that go from the parent to the children.

Set http://gojs.net/latest/api/symbols/Diagram.html#isTreePathToChildren to false when you initialize your diagram:

        isTreePathToChildren: false,