By clicking this, user will be able to filter the flight by Time, Stops, Airlines along with Staring Price, Refundable, Nearby airport (user will find more options apart from the entered international destination)
Apply button will save and apply the filters on flight results. once user has applied filter on trip-1 and moved to trip-2, then the filters applied on trip-1 will be autosaved and vice-versa.
Rules and Validations:
Nearby Airport is applicable for International flights and will be available in the availability response. User can select more than one filtering criteria to filter results as a combination of different filters. User should be able to filter onward and return flight separately in case of Roundtrip search