Data tables Grouping for rows with child colums

kimigx

I am using DataTables and based on this example;
https://datatables.net/examples/advanced_init/row_grouping.html)
I would like to adapt it to GROUP ROWS WITH CHILD ROWS WITHOUT AFFECTING THE CHILD ROWS.

I.e. based on the above example from the link, I would like to group all the employees based on office location and considering the fact that each row employee might have childrows eg, telephone email, etc

I would highly appreciate it. if someone comes to my aid on this