Devise\Media\Files\Filesystem::search PHP Method

    public function search($directory, $pattern)
    {
        $finder = new Finder();
        $finder->files()->in("{$directory}")->name("*{$pattern}*");
        return $finder;
    }

 /**
  * Get
  * @param $currentDirectory
  * @param $searchFor
  * @return array
  */
 private function buildSearchedItems($currentDirectory, $searchFor)
 {
     if (!$searchFor) {
         return array();
     }
     $files = $this->Filesystem->search($currentDirectory, $searchFor);
     return $this->buildMediaItemsFromFiles($files);
 }