Here is a tutorial that might be helpful. The example for allowing multiple users to share their locations with everyone uses the CloudDB. You can replicate the app using the FirebaseDB. The controls are very similar.
Social Distancing ... a CloudDB / Location Marker Tutorial
The Project
Determine how close an individual you share an app with is to you. You use a CloudDB, LocationSensor/GPS receiver, Map component, design time Markers and a StayAwake routine. Sound an alarm when someone comes too close or just have fun with the app to keep track of your family circle's whereabouts. Observe where everyone is on a Map. The app continually updates and calculates distance separation.
The Social Distancing s…
or possibly this one
[bus2] How to broadcast a GPS location and share the information on a map in real time.
Two similar apps explore the basics of how to share a location using a single screen and a real time database. One app user beacons, the others monitor (view his/her) location map using the same app.
Share Your Location is a basic app to share a map of your location with others who have installed your app. The example tracks a single user who beacons his/her location. Provide separate Tags for other u…
Sorry, I do not understand this. Could you provide an example?