Get rid of nested rows. Convert nested rows to root rows

Hi there!
How can I convert this:

To this:

The idea behind this is to get rid of nested rows and to convert them to simple root rows by iterating over each leaf and concatenating parent values to it’s value. And then moving them somehow to level 1. This may possibly be achieved by using eachChild method but I am not sure how exactly.
Thanks!

https://snippet.webix.com/jxofqska

Hi there intregal
Many thanks for quick reply. You guys are awesome. Never regretted buying your product.
This approach looks promising. But in my case it is unacceptable to have original fields in “rows” section replaced with new “combined” field. Is there any other approach to achieve this? Or maybe we could try visually replacing “combined” field with original fields on each popup opening?
Thanks!

something like this?
https://snippet.webix.com/51ya5jao