Shortcode for overall rating of sub rating

function.php

<?php
/**
 * This code create a shortcode [buddy-overall-rating].
 * It can be used on archive item template.
 */
add_shortcode( 'buddy-overall-rating', function($args){
    $plugin_public = new GeoDir_Review_Rating_Manager_Public();
    return $plugin_public->show_overall_multiratings();
});