Trying to get a ansible tower job to run on survey-variable based inventories?

Question

I am using ansible tower and aiming to do something like this. Lets say I have these inventories defined in ansible tower

kanto-pkmn   unova-pkmn       johto-pkmn  
a            e                c
b            f                d        

Now I want the user to input variables (say he enters kanto and unova) then the script is only supposed to run on those hosts. However the catch is the hosts are supposed to mantain some form of variable that connects them to their respective inventory.

(ex. some sort of mapping should be there between a and kanto)

Ideas I have explored:

Multiple inventories seems like the best way but ansible tower only allows one inventory to be set during a job

Smart inventory is another option but it seems that it removes all the groups of the previous inventory so all I seem to obtain is

a
b
c
f
e
f

Is there any way I can get something like smart inventory with the groups intact or basically get something like

[kanto-pkmn] (or anything that can be mapped to the file)
a
b
[unova-pkmn]
e
f

Answer 1

Ansible Inventory

    [kanto-pkmn]
    a
    b
    
    [unova-pkmn]
    e
    f
    
    [johto-pkmn]
    c
    d
    
    [kantounova:children]
    kanto-pkmn
    unova-pkmn

Run aginst ansible inventory

    ansible all -m setup         **--> will run on all (builtin feature)**
    ansible unova-pkmn -m setup  **--> will run on c and d**
    ansible kantounova -m setup  **--> will run on a,b,e, and f**
    

Ansible Playbook

    In your playbook or role you want to run you can add survey questions 
    
    - name: Install Lab Environment
      become: true
      hosts: johto-pkmn

      vars_prompt:
      - name: rhn_username     *-->this is your variable name**
        prompt: Enter Red Hat CDN username
        private: no

      - name: rhn_password
        prompt: Enter Red Hat user CDN password
        private: yes

       - name: ORG
         prompt: What is the name of your organization?
         private: no  

      - name: LOC
        prompt: Please enter the location of your env
        private: no 

    tasks:
      - name: Register with red hat cdn and attach rhel subscription
        redhat_subscription:
          username: "{{ rhn_username }}"
          password: "{{ rhn_password }}"
          state: present
          pool: '^Red Hat Ansible Automation'
        when:
          - rhn_username != ""
          - unova in group_names  **<-- this would run on abc and d if they have a rhn_username**