There is no direct way to do it.
However it can be done some other way. Follow these steps.
1. Copy the child node where you want to insert in between
2. Delete the entire tree from the point where youwould like to insert a node
3. Then add a child
4. Then paste the whole tree under that node.
This is a cumbersome way to do that operation. But it works.
We shall try to implement a more direct way.