Sure, sorry I was not able to answer yet.
This is a tough one. I think that using a custom script for this for the front-end search would be the easiest solution. Some sort of an event listener on the location input, and wherever the desired values are selected, hide the other two address inputs (and possibly reset them).
This may require decent amount of custom coding though. I definitely recommend javascript for this, instead of a back-end (PHP) solution.