How can we access sibling nodes and path of sibling node

Thanks in advance, any suggestions would be appreciated.
**This is the tree**
* Parent-1
* Child-1.1
* Parent-2
* Parent-3
* Child-3.1
* Child-3.2
* Child-3.3

Here I want to move Child-3.3 to Child-3.2 as its children, without using mouse drag and drop.
The new tree will look something like this.

* Parent-1
* Child-1.1
* Parent-2
* Parent-3
* Child-3.1
* Child-3.2
* Child-3.3