If you are someone who has not turned off the location settings, then once you open the Facebook App you might find that the location is already there. If you would like to change the current location, follow the steps below:
1. Open Facebook app, then go to your profile and edit it.
2. In the "Details" section, you'll see the location information. Tap it.
3. Edit the "Current City" as you like. Then save the change.