How To Get Started
To get this done, kindly make sure you logged in to Facebook via a Computer. Not sure if this trick work on other devices for now.
STEPS
Click inside the “What is on your mind” box
Then, click the 
icon under the box as seen in the picture below:
Type in the name of your location in the “Where are you?” text area. While typing, you might see some suggestions. You can click on any of the suggestions if it matches your location.
You should then see the location beside the icon and also in the “What is on your mind” box.
Click on the “Post” button to update your Facebook status, so that your new location can be enabled on your profile.
Thereafter, the location will start appearing next to the timestamp of your Facebook Status updates. So, the next time you post, your general location will be added to that post. It’ll stay on for future posts until you remove it. Once removed, it’ll stay off until you add it back to your post.
I hope this helps.
Cheers!