system/classes/Framework.php
protected function getPathBackslash($pathname, $removeBaseName = false) {
        $arr = explode('\\', $pathname);
        if ($removeBaseName) {
            $partialPathArray = array_slice($arr, 1, count($arr)-2);
        }
        else {
            $partialPathArray = array_slice($arr, 0, count($arr)-1);
        }
        array_walk($partialPathArray, array($this, '_lcfirst'));
        $path = implode('/', $partialPathArray);

        // If path isn't blank, then add ending slash to it.
        if ($path != '')
            $path = $path . '/';

        return $path;
    }
protected function getPathBackslash($pathname, $removeBaseName = false) {
        $arr = explode('\\', $pathname);
        if ($removeBaseName) {
            $partialPathArray = array_slice($arr, 1, count($arr)-2);
        }
        else {
            $partialPathArray = array_slice($arr, 0, count($arr)-1);
        }
        array_walk($partialPathArray, array($this, '_lcfirst'));
        $path = implode('/', $partialPathArray);

        // If path isn't blank, then add ending slash to it.
        if ($path != '')
            $path = $path . '/';

        return $path;
    }
Get the 'folder/folder' out of 'folder\folder\fileName.php