Popup work with tree

Hi, guys,I’m trying to implement that when I click on a tree node, a pop-up window will pop up below the tree node. I plan to use show( ),but I don’t know how to set the container to place a popup in.

Tree itemClick event has the event object as a second attribute:

You can use it to get the html element of the item.
Here is the example:
https://snippet.dhtmlx.com/xa4qhoyr