FacetWP Listing Builder with ACF repeater subfields

<?php
/** 'author' is the Unique name set in the Listing Builder item's settings.
 ** Loop over the array returned from ACF to build an HTML string from the subfields and return it to the Listing Builder's
 ** facetwp_builder_item_value filter
 **/

add_filter( 'facetwp_builder_item_value', function( $value, $item ) {
	if ( 'author' == $item['settings']['name'] ) {
		$value = '';
		$authors = get_field( 'author' );
		if ( !empty( $authors ) ) {
			foreach ( $authors AS $author ) {
				$value .= $author['title'] . ' ' . $author['name'] . '<br />'; // create an html string formatted as needed to return
			}
		}
	}
	return $value;
}, 10, 2 );