Display posts by taxonomy and taxonomy child

I am trying to show my CPT posts grouped by child taxonomies (in archive-CPT.php) in something that looks like this…

Parent taxonomy 1
Child Taxonomy 1
* Post 1
* Post 2

Child Taxonomy 2
* Post 3
* Post 4

Parent taxonomy 2
Child Taxonomy 1
* Post 5
* Post 6

Child Taxonomy 2
* Post 7
* Post 8

What I have so far is:
Parent taxonomy 1
Post 1
Post 2
Post 3
Post 4

Parent taxonomy 2
Post 5
Post 6
Post 7
Post 8

My code is as follow:

Any help would be really apreciated!

Thanks!