Accessing element in a merged list - ansible

Question

I'm trying to create a playbook that's going to create multiple files in a number of different directories. The input variables are env & region and both are lists. I've then combined them to display all the different combinations.
What I want is to then loop through all the different folder paths by accessing the values of each individual list, and this is where I'm stuck.
---
- hosts: localhost
gather_facts: false
become: no
vars:
application_name: test
region: [us-east-1, us-east-2]
env: [test,prod]
tasks:
- name: allregions_and_enviroments
set_fact:
all_comb: "{{ region|product(env) }}"
- debug:
var: all_comb
- name: Create new TF file
template:
src: template.j2
dest: /Users/user/Documents/ansibletemplate/{{item[0]}}/{{item[1]}}/ab-{{application_name}}.tf
with_nested: all_comb
The output of the merged list is this:
ok: [localhost] => {
"all_comb": [
[
"us-east-1",
"test"
],
[
"us-east-1",
"prod"
],
[
"us-east-2",
"test"
],
[
"us-east-2",
"prod"
]
]
}
In the directory path, I want it to loop through the region and then the environment and create a file in ..../us-east-1/test/abc.tf then move on to the next.
Any assistance will be greatly appreciated.
Thanks!