vars:
    env: 'dev'

...

    - name: add and remove several users
      user:
        name="{{ item.username }}"
        uid="{{ item.uid }}"
        comment="{{ item.comment }}"
        state="{{ item.state }}"
        remove="{{ item.remove }}"
        groups="{{ admin_group.stdout }}"
        password="{{ item.password }}"
        update_password="always"
#     when: "{{item.env}} == {{env}}"
#     when:
#       - (skip_users != True)
#       - ( {{item.env}} == environment)
#       - "{{item.env}} == {{env}}"
#       - ( {{item.env}} == env)
      with_items:
        - { username: 'admin1',     uid: '1000', comment: 'admin1',    state: 'present', remove: 'yes', groups: 'wheel',
            env: 'test',
            password: '$redacted$' }
        - { username: 'admin2',     uid: '1000', comment: 'admin2',    state: 'present', remove: 'yes', groups: 'wheel',
            env: 'dev',
            password: '$redacted$' }