ACFBS - search by ACF fields only

functions.php

function stfn_acfbs_post_fields( $fields ) {
    // default lista: ['post_title', 'post_content', 'post_excerpt']
    $fields = [];
    return $fields;
}
add_filter( 'acfbs_search_post_object_fields', 'stfn_acfbs_post_fields', 10, 1 );