How to make map distance searchable (without ZIP)

Hello to all, i am looking for a way to create a custom search field in Directory Theme, that i can search the distance between the user’s location and the listing location.

When i submit a listing, i get the distance because [DISTANCE] shortcode is there but it doesn’t exist in the custom fields search field.

I would like to create a drop down box with distances like: 1, 5, 10, 25 and 50 km and search for listings within the selected distance.

Is this possible somehow? I do not want to use the ZIP solution!

Thank you very much!