FacetWP – change cluster icons

<?php

/**
 * This assumes a "gmaps" folder within your theme
 * Within that folder, add m1.png, m2.png, m3.png, m4.png, m5.png
 */
add_filter( 'facetwp_map_init_args', function( $settings ) {
    $settings['imagePath'] = get_bloginfo( 'stylesheet_directory' ) . '/gmaps/m';
    return $settings;
});