Ansible conditional with variable

I have to build a cluster where certain packages should be installed on all hosts while other packages are installed on specific hosts only.

I wish to add a conditional to my yum install loop to select the target host based on my inventory groups (master, slave, all).

- name: Install Package
  when: inventory_hostname in groups[ {{item.host }} ]
  yum:
    name: "{{ item.name }}"
    state: present
  loop:
    - {name: 'package_1', host: 'master'}
    - {name: 'package_2', host: 'slave'}
    - {name: 'package_3', host: 'all'}

I understand that jinja2 templating is not an option, but I couldn't find what is the right way to do it. Thanks!