adlerka.space/templates/navpages.php

<?php
ob_start();

$navsite_template = '<li><a class="navsite_link" href="__LOCATION__" __CLASS__>__NAME__</a><ul class="navpage_list"></ul></li>';
$navpage_template = '<li><a class="navpage_link" href="__LOCATION__" __CLASS__>__NAME__</a></li>';

$page_dir = "pages";

$site_dirs = array_diff(scandir($page_dir), array('.', '..'));

$domain = basename(explode('.', $_SERVER['HTTP_HOST'])[1]);
$tld = basename(explode('.', $_SERVER['HTTP_HOST'])[2]);

foreach($site_dirs as $site_dir){
    $pages_dir = array_diff(scandir("$page_dir/$site_dir"), array('.', '..'));
    $navpages = "";
    foreach($pages_dir as $page_dir){
        $navpage = $navpage_template;
        $navpage = 
        $navpages .= $navpage;
    }
}

return ob_get_clean();

?>