facetwp copy range to dropdown

custom-hooks.php

<?php
/** create a range list facet with the ranges you need
 ** create a dropdown facet with any datasource, post type is good its just a placeholder
 ** change the code below to match your facet names
 **/

add_filter( 'facetwp_index_row', function( $params, $class ) {
	if ( 'my_range_facet' == $params['facet_name'] ) { // change 'my_range_facet' to the name of your range list facet
		$params['facet_name'] = 'dropdown_range'; // trick FacetWP into saving values into the other facet
	} elseif ( 'dropdown_range' == $params['facet_name'] ) { // change 'dropdown_range' to the name of your dropdown facet in this and the above line 
		$params['facet_value'] = ''; // skip indexing
	}
    return $params;
}, 10, 2 );