Nevermind. I solved it. It was simple. I should have seen it before I posted.
//DOMAIN NAME
$sitename = $_SERVER['HTTP_HOST'];
//PAGE NAME - NO SLASH
$pathwithrequesturi = $_SERVER['REQUEST_URI'];
$foldername = ltrim($pathwithrequesturi, '/');
//DIRECTORY NAME - NO SLASH
$pathwithdirname = dirname($pathwithrequesturi);
$directoryname = ltrim($pathwithdirname, '/');
print "Sitename only: ".$sitename."<br><br>";
print "Page: ".$pathwithrequesturi."<br><br>";
print "Page (no slash): ".$foldername."<br><br>";
print "Directory: ".$pathwithdirname."<br><br>";
print "Directory (no slash): ".$directoryname."<br><br>";