Group trigger - get entity which triggered group change

5 
    message: >
      No-one is home and the alarm isn't set!

      Last person to leave was:

      {{ ( expand('group.family')
        | sort(reverse=true, attribute='last_changed')
        | map(attribute='name')
        | list )[0] }}

      But it might have been:

      {{ ( expand('group.family')
        | sort(reverse=true, attribute='last_changed')
        | map(attribute='name')
        | list )[1] }}

      Punish them both just in case!