WP Travel trips achieve filters by listing type.

Source

File: /inc/helpers.php
Used by: /inc/helpers.php

Parameters
$list_type. Default is ‘default’.

Example:

function prefix_wp_travel_trip_archive_filter_by( $list_type ) {
    $list_type = ‘LIST BY TYPE’;
    return $list_type;
}
add_filter( 'wp_travel_trip_archive_filter_by', 'prefix_wp_travel_trip_archive_filter_by' );