Hide free levels if user is logged in - Paid Memberships Pro

pmproc_hide_free_levels.php

<?php 

//Copy lines 5 ownards into your custom PMPro plugin -> http://www.paidmembershipspro.com/create-a-plugin-for-pmpro-customizations/

function pmproc_hide_free_levels($levels){
    if( is_user_logged_in() && pmpro_hasMembershipLevel() ){ //check if user is logged in and has a membership level
    $newlevels = array();
      foreach($levels as $level){
          if(!pmpro_isLevelFree($level)){
            $newlevels[] = $level;
          }
      }   
      return $newlevels;
    }
    return $levels;
}
add_filter("pmpro_levels_array", "pmproc_hide_free_levels");