Here is how to clear google maps history on iPhone or iPad..
1. Go to Google Maps app on your iPhone
2. Go to menu section and tap Settings
3. Tap Map history
4. Touch X (delete), to delete the entry you want
5. Touch Delete.
Here are the screenshots
1. Go to Google Maps app on your iPhone
2. Go to menu 
3.Tap Settings
3. Tap Map history
4. Touch X (delete), to delete the entry you want
5. Touch Delete.
