This feature is an extension of the Geographic Navigation Addon feature and requires that addon to be in use before this feature can be used. This feature automatically sets the country level filter of the Geographic Navigation Addon when the client first visits your site.
Highlights of the Geolocation feature:
Look to the following to turn on/off that feature:
ADDONS > GEOGRAPHIC NAVIGATION > SETTINGS > BETA / Experimental: Automatically assign visitors' regions based on their IPs
Once the above is checked you should see the following:
You'll need to setup an account with ipinfodb.com and insert the API key you get from them within the above noted field