PHP - Return array of parents from multidimensiona

I'm trying to create dynamic breadcrumbs from an array. So I can add to the array and not have to manually update the breadcrumbs.

Okay, here's a snippet of my array: (It won't go much deeper)

$menu = array(
    'Dashboard' => array(
        'Projects' => array(
            'Project 1' => array(
                'Project settings' => 'projects/project_1/settings',
                'Issue Tracker' => 'projects/project_1/issue_tracker',
                'Customize page' => 'projects/project_1',
                'Manage files' => 'projects/project_1/files',
            ),
            'Project 2' => array(
                'Project settings' => 'projects/project_2/settings',
                'Issue Tracker' => 'projects/project_2/issue_tracker',
                'Customize page' => 'projects/project_2',
                'Manage files' => 'projects/project_2/files',
            ),
        ),
        'Logout' => '#',
    )
);

I would like to be able to return all the parents of any key in a way that I can iterate through later. For instance, for 'Project settings':

'Dashboard','Projects','Project 1'.

In your example there are actually two paths possible:

Key 'Project settings' found: 'Projects' -> 'Project 1'
Key 'Project settings' found: 'Projects' -> 'Project 2'

You can easily solve this with a recursive iterator (See RecursiveIteratorIterator it offers all you need). I chose it because it allows you to easier search and obtain the parent levels keys:

$search = 'Project settings';
$it     = new ParentKeysIterator($menu);
foreach ($it as $key) {
    if ($key !== $search) continue;
    printf("Key '%s' found: '%s'\n", $key, implode("' -> '", $it->key()));
}

And the ParentKeysIterator:

class ParentKeysIterator extends RecursiveIteratorIterator
{
    public function __construct(array $array) {
        parent::__construct(new  RecursiveArrayIterator($array));
    }

    public function current() {
        return parent::key();
    }

    public function key() {
        return $this->getParentKeys();
    }


    public function getParentKeys() {
        $keys = [];
        for ($depth = $this->getDepth() - 1; $depth; $depth--) {
            array_unshift($keys, $this->getSubIterator($depth)->key());
        }
        return $keys;
    }
}