Me neither. Should be found in General settings on iPhone, rather than via Google Maps (seems to be the only way, from what I can tell?)
iPhone GPS Location (4s and recent)
This document will give you a step by step procedure to retrieve the GPS location of a lost person using the “Compass” tool. In order to use this tool, the iPhone owner must enable some privacy settings which may be “on” by default. If you cannot get the GPS coordinates from Compass, go to the “Troubleshooting” section.
Asking for GPS Coordinates First ask the lost person to launch the compass application on their iPhone.
If the person does not know what it is, provide them the following instruction: Put a single finger in the middle of the phone’s screen and swipe down all in one move. This will bring out the “Spotlight Search” tool.
Ask them to type “Compass”. This will bring up the “Compass” tool into view as seen below: Ask them to select the “Compass” application in order to launch it
Once launched, if the word “Calibrate” appears on the screen (as seen below), the user has to initialize the application. Let him know he needs to move and rotate the phone until calibration is done.
Once calibrated, the user should see the coordinates at the bottom of the screen. If the coordinates are not there, go to the troubleshooting section and restart this process from step 1.
Troubleshooting Be aware that only iPhone 4s and more recent are equipped with a GPS chipset. All older iPhone will not be able to provide you with GPS coordinates.
In order for the “Compass” application to provide the GPS coordinate, it needs to be authorized to communicate with the GPS component of the phone. To ensure this authorization is set, follow these steps:
Ask the person to launch their iPhone settings
From the main “Setting” page, have them select “Privacy”
From the “Privacy” section select “Location Services”.
Under the “Location Services” section, the “Location Services” setting should be “on” (or green) and the “Compass” entry should report “While Using”.