FacetWP – index 2 autocomplete sources

<?php

add_filter( 'facetwp_indexer_row_data', function( $rows, $params ) {
    if ( 'keyword' == $params['facet']['name'] ) {
        $new_row = $params['defaults'];
        $post_id = (int) $new_row['post_id'];
        $new_row['facet_value'] = $post_id,
        $new_row['facet_display_value'] = get_the_title( $post_id );
        $rows[] = $new_row;
    }
    return $rows;
}, 10, 2 );