Here are a few example topics:
myhome/groundfloor/livingroom/temperature USA/California/San Francisco/Silicon Valley 5ff4a2ce-e485-40f4-826c-b1a5d81be9b6/status Germany/Bavaria/car/2382340923453/latitude
Wildcards
Single Level: +
Multi Level: #
References
https://www.hivemq.com/blog/mqtt-essentials-part-5-mqtt-topics-best-practices