Description:
------------
Currently, its difficult to extend RecursiveFilterIterator() with additional __construct() arguments (for configuring its behavior).  The reason its difficult is b/c when getChildren() is called, a new instance of the RFI is created (only way you'd know this is if you look into the source of RFI).

Workaround currently is this (But is not generic enough to all use cases):

replace getChildren():

    function getChildren()
    {
        if (empty($this->ref)) {
            $this->ref = new ReflectionClass($this);
        }
        return $this->ref->newInstance($this->getInnerIterator()->getChildren(), $this->_otherArgs);
    }

Reproduce code:
---------------
$rArray = array('a' => array('ab', 'ac', 'ad' => array('ada', 'adc')), 'b' => array('bb', 'bc'));

$ri = new RecursiveArrayIterator($rArray);
$filter = new MyRFI($ri, 'argument');
$iterator = new RecursiveIteratorIterator($filter);

foreach ($iterator as $key => $item) {
    echo $key . ' - ' . $item . PHP_EOL;
}

class MyRFI extends RecursiveFilterIterator
{
    protected $_otherArg = null;

    public function __construct($iterator, $otherArg = null)
    {
        $this->_otherArg = $otherArg;
        parent::__construct($iterator);
    }

    public function accept()
    {
        echo ($this->_otherArg) ? 'Arg Present' : 'Arg NOT Present';
        echo PHP_EOL;
        return true;
    }
}

Expected result:
----------------
Arg Present
Arg Present
0 - ab
Arg Present
1 - ac
Arg Present
Arg Present
0 - ada
Arg Present
1 - adc
Arg Present
Arg Present
0 - bb
Arg Present
1 - bc 

Actual result:
--------------
Arg Present
Arg NOT Present
0 - ab
Arg NOT Present
1 - ac
Arg NOT Present
Arg NOT Present
0 - ada
Arg NOT Present
1 - adc
Arg Present
Arg NOT Present
0 - bb
Arg NOT Present
1 - bc