Primera letra de cada custom post type

[wpv-layout-start]
    [wpv-items-found]
    <a href="[current_url]">All</a>
    <!-- wpv-loop-start -->
        <wpv-loop>
            <a href="?wpvalphabet=[wpv-taxonomy-title]">[wpv-taxonomy-title]</a>
        </wpv-loop>
    <!-- wpv-loop-end -->
    [/wpv-items-found]
    [wpv-no-items-found]
        <strong>[wpml-string context="wpv-views"]No items found[/wpml-string]</strong>
    [/wpv-no-items-found]
[wpv-layout-end]

add_shortcode( 'current_url', function(){
    
    $request = $_SERVER['HTTP_HOST'].strtok($_SERVER["REQUEST_URI"],'?');
    $protocol = 'http://';
    
    if ( isset($_SERVER['HTTPS']) ) {
        $protocol = 'https://';
    }
    
    return $protocol . $request;
} );

wpv-layout-start]
[wpv-view name="alphabet-terms"]
[wpv-items-found]
<!-- wpv-loop-start -->
        <wpv-loop>
            <h3>[wpv-post-link]</h3>
        </wpv-loop>
    <!-- wpv-loop-end -->
    [/wpv-items-found]
    [wpv-no-items-found]
        <strong>[wpml-string context="wpv-views"]No items found[/wpml-string]</strong>
    [/wpv-no-items-found]
[wpv-layout-end]

add_filter('wpv_filter_query', 'func_filter_by_title', 10, 2);
function func_filter_by_title($query, $setting) {
  
global $wpdb;
      
if($setting['view_id'] == 9999) {
          
        if(isset($_GET['wpvalphabet']) and $_GET['wpvalphabet']!='' ){
              
              
            $first_char = $_GET['wpvalphabet'];
            $postids = $wpdb->get_col($wpdb->prepare("SELECT      ID
                                                        FROM        $wpdb->posts
                                                        WHERE       SUBSTR($wpdb->posts.post_title,1,1) = %s
                                                        AND post_type = '".$query['post_type'][0]."'
                                                        AND post_status = 'publish'
                                                        ORDER BY    $wpdb->posts.post_title",$first_char)); 
                                                          
                  $query['post__in'] = $postids;
                  }
  }
return 

https://toolset.com/forums/topic/show-hidden-links/#post-1612419