Multiple nested angular drag and drop

I have a page where from one DIV take items and put them to another div. I use angular Drag and Drop for this. I can take the item and put them to the root of div, or to another nested div, etc... Also all of this dropped item I need to move to another div and move parent and child div. And I need to export all of this data to JSON.

Thnx

Here is stackblitz to see what I need.

And here is an explanation in picture