Permalink category/region

Hi,
currently working on a directory site with WP Job Manager integrated in it
I am using the snippet that I found here
https://wpjobmanager.com/document/tutorial-changing-the-job-slugpermalink/
Before I had
mysite.com/listing/listing-category/mylistingname

works well and I now have
mysite.com/experience/listing-category/Listing-Region/mylistingname
I would love to have subcategories of my listing-categories and sub-regions
The snippet has an array on the $first_term and I am pretty sure that is why my slug is only showing term1 of the categories and term 1 of the region

Could any one help me telling me how I can get my child categories and child regions to show as well ???

Thank’s in advance