/**
 * Modifies the review values before they are saved
 * Paste this in your active theme's functions.php file.
 * @param array $values
 * @param \GeminiLabs\SiteReviews\Commands\CreateReview $command
 * @return array
 */
add_filter('site-reviews/create/review-values', function ($values, $command) {
    // If the user is not logged in
    // Or, if the review was NOT submitted with the specified Review Form
    // Then abort!
    if (!is_user_logged_in() || 21084 != $command->request->form) {
        // return the unchanged values
        return $values;
    }
    // get the logged in user
    $user = wp_get_current_user();
    // get a Post ID from the provided URL
    $postId = url_to_postid('https://www.xyz.com/'.$user->user_nicename);
    // get the post object from the Post ID
    $post = get_post($postId);
    // proceed if the the post object was found; also ensure that the "geodir_get_post_meta" function exists
    if ($post && function_exists('geodir_get_post_meta')) {
        // get the region
        $region = geodir_get_post_meta($post->ID, 'region', true);
        // get the city
        $city = geodir_get_post_meta($post->ID, 'city', true);
        // get the date
        $date = do_shortcode('[geodir_event_schedules type="upcoming" number="1" template="{start_date} - {end_date}" use_current="1"]');
        // finally, change the review title
        $values['title'] = $city.', '.$region.', '.$date;
    }
    // always return the review values!
    return $values;
}, 10, 2);