You can track users' phone numbers via Google Maps if you ask them to share them.  Step 1: Access the Google Maps app through an Android/iOS phone.  Step 2: Tap on top of your account avatar visible at the top-right side of your screen.  Step 3: Then, choose Location sharing in the popup that appears.  Step 4: Select a contact and then press "Request". The person would get the information and allow the tracking request.