You can't change Your current location from settings.
If you want to save selected city as your current location then save selected city's longitude and latitude and pass it as your current location to method that gets the near by events so it should work as your current location.
You can save your selected city lat n long in Preference file (or .plist). and when Location updates itself you can check if user have selected city then you pass the lat and long of selected city otherwise your current location lat long. so it will be easier for you.
Hope it Helps!!