Filter or Action before submitting Search button

Hello!

Is there an action or filter we can use to customize the data being sent before submitting the Search form?

Our goal is to manually set the set_location_val in the backend.

Because currently, if the user did not select a value in the autocomplete list, it is not returning the correct data.
We want to still show results without selecting a value from the autocomplete list.

Hoping there is a filter or action we can use to do that.
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Example:
Link: http://pelvicguru.com/directory
Try searching for Canada.
If you select the autocomplete value (Country: Canada), there will be 4+ pages of result.
If you typed in Canada and hit enter without waiting for the autocomplete list, it will not return any result.