Welcome Terence.
Yes, modify this tutorial or perhaps modify the Social Distancing tutorial to track multiple busses (or people) who have the app turned on.
You need an Android with the shared app active and broadcasting its location , Each user will have to broadcast its own present location and be associated with a Marker for each bus. Then you can plot multiple 'busses'.
Instead of always saving in the tag myLocation you could StoreValue as a Tag named Bus1Location for one user and Bus2Location for another user similar to what is done in the Social Distancing tutorial for four (4) persons (in your case buses). See
and adapt that tutorial to only show the locations perhaps. This example can display a map showing your location and the locations of others that have the app. Provide a design time Marker for each bus. With considerably more complexity and difficulty you could also program the app to use run time Markers. Try with design time Markers first (Marker1, Marker2, etc.)
What have you tried?
Alternatively to a CloudDB , consider an app that will post the user's location to a GoogleSpreadsheet if you have advanced App Inventor coding skills.