array_multisort

$sortArray = array();

foreach($displays as $display){
foreach($display as $key=>$value){
if(!isset($sortArray[$key])){
$sortArray[$key] = array();
}
$sortArray[$key][] = $value;
}
}

$orderby = $groups[0];

array_multisort($sortArray[$orderby],SORT_DESC,$displays);
print_r($sortArray);exit;