Redirect WordPress to Subfolder from Non-Base Domain

functions.php

<?php

// Redirects brooklynkindershule.org to campkinderland.org/shule and respects sub paths
function custom_rewrite_basic() {
  if( $_SERVER['SERVER_NAME'] == 'brooklynkindershule.org') {
	  $location = 'http://campkinderland.org/shule';
	  if( $_SERVER['REQUEST_URI'] && $_SERVER['REQUEST_URI'] != '/shule' ) $location .= '/'.$_SERVER['REQUEST_URI'];
	  header( 'Location: '.$location );
  }
}
add_action('template_redirect', 'custom_rewrite_basic');

?>