Ansible search sublists for value - ansible

Question

A webhook triggers an AWX job and I want to run the deployment on a certain host depending on the service, since they run on different servers. I need to know which server uses that service to set is as a var so it can be used as a host in the following play.
My variable inside vars.yaml looks like this:
staging_hosts:
server1: ['service1', 'service2', 'service3']
server2: ['service4', 'service5', 'service6']
server3: ['service7', 'service8', 'service9']
Playbook:
- name: write deployment hosts
hosts: localhost
vars:
deployment_hosts: absent
vars_files:
- ./group_vars/vars.yaml
tasks:
- set_fact:
modified_repos: (small regex filter to find modified repository)
- set_fact:
deployment_hosts: "{{ item }}"
when: '{{ modified_repos }} in {{ item }}'
with_list:
- "{{ staging_hosts }}"
- name: connect to Cluster
hosts: "{{ hostvars['localhost']['deployment_hosts'] }}"
What can I do against this warning and error?
[WARNING]: conditional statements should not include jinja2 templating
delimiters such as {{ }} or {% %}. Found: {{ modified_repos }} in {{ item }}
fatal: [localhost]: FAILED! => {"msg": "The conditional check '{{ modified_repos }} in {{ item }}' failed. True {% else %} False {% endif %}): unhashable type: 'list'
Oh I forgot to mention. It is important, that deployment_hosts could also contain two hosts if modified repos include for example service1 and service4.

Answer 1

Q: "deployment_hosts could also contain two hosts if modified repos include for example service1 and service4."
A: Use intersect filter. For example, the playbook
- hosts: localhost
vars:
staging_hosts:
server1: ['service1', 'service2', 'service3']
server2: ['service4', 'service5', 'service6']
server3: ['service7', 'service8', 'service9']
modified_repos: ['service1', 'service4']
tasks:
- set_fact:
deployment_hosts: "{{ deployment_hosts|default([]) + [item.key] }}"
loop: "{{ staging_hosts|dict2items }}"
when: modified_repos|intersect(item.value)|length > 0
- debug:
var: deployment_hosts
gives
deployment_hosts:
- server1
- server2