admin/controller/common/filemanager.php

bul altına
$directories = glob($directory . '/' . $filter_name . '*', GLOB_ONLYDIR);

ekle
usort($directories, create_function('$a,$b', 'return filemtime($a) - filemtime($b);'));

tersini istersen
usort($directories, create_function('$a,$b', 'return filemtime($b) - filemtime($a);'));