This is not my idea and i can’t find the topic where it’s mentioned.
You can use the MQTT Device Tracker for this.
Just set it up, and create automations that publish the state of the group to the given topic.
Example:
group.person1 to on
- service: mqtt.publish
data:
topic: 'home/people/person1'
payload: 'home'
group.person1 to off
- service: mqtt.publish
data:
topic: 'home/people/person1'
payload: 'not_home'
Then use the mqtt device tracker for your dashboard.
EDIT:
Found it! Thanks @Cezex