This filter enables you to modify the parameters included in the geocode component filter.
If you, for example, search for Springfield, then the first result the Geocode API returns is located in Massachusetts. Which is fine if your store is actually located in Massachusetts, but if it’s located in Illinois, then the only thing the user will see is a “No results found” message.
To fix this you can use this filter to restrict the results by administrativeArea, country, locality, postalCode and route.
This example restricts the returned geocode results to Illinois:
This filter is located in /frontend/class-frontend.php