How to select every child of siblings array with a specific selector without a loop?

I have the following navigational menu:

<nav id="nav-primary" class="text-center">
    <button id="menu-main-toggle" class="dropdown-toggle script-dependant active">Menu</button>
    <ul id="menu-main" class="nav toggleable hide">
        <li class="menu-item odd first"><a class="menu-link" href="//localhost:3000/index.php/about/">About</a>
        </li>
        <li class="menu-item even"><a class="menu-link" href="/index.php/category/bahrain/">Bahrain</a>
        </li>
        <li class="menu-item odd parent"><a class="menu-link" href="/index.php/category/information-technology/">Information Technology</a>
            <button class="dropdown-toggle script-dependant">+</button>
            <ul class="toggleable hide">
                <li class="menu-item odd first parent"><a class="menu-link" href="/index.php/category/information-technology/web-development/">Web Development</a>
                    <button class="dropdown-toggle script-dependant">+</button>
                    <ul class="toggleable hide">
                        <li class="menu-item odd first"><a class="menu-link" href="/index.php/category/information-technology/web-development/html/">HTML</a>
                        </li>
                        <li class="menu-item even"><a class="menu-link" href="/index.php/category/information-technology/web-development/css/">CSS</a>
                        </li>
                        <li class="menu-item odd last"><a class="menu-link" href="/index.php/category/information-technology/web-development/javascript/">Javascript</a>
                        </li>
                    </ul>
                </li>
                <li class="menu-item even last"><a class="menu-link" href="/index.php/category/information-technology/unix/">Unix</a>
                </li>
            </ul>
        </li>
        <li class="menu-item even parent"><a class="menu-link" href="http://lipsum.com">Lorem</a>
            <button class="dropdown-toggle script-dependant">+</button>
            <ul class="toggleable hide">
                <li class="menu-item odd first parent"><a class="menu-link" href="http://lipsum.com">Ipsum</a>
                    <button class="dropdown-toggle script-dependant">+</button>
                    <ul class="toggleable hide">
                        <li class="menu-item odd first last"><a class="menu-link" href="http://lipsum.com">Dolor</a>
                        </li>
                    </ul>
                </li>
                <li class="menu-item even last"><a class="menu-link" href="http://lipsum.com">Situs</a>
                </li>
            </ul>
        </li>
        <li class="menu-item odd"><a class="menu-link" href="/index.php/category/snippets/">Snippets</a>
        </li>
        <li class="menu-item even last"><a class="menu-link" href="//localhost:3000/index.php/contact/">Contact</a>
        </li>
    </ul>
</nav>

Every li.parent has a .dropdown-toggle button. When the button is clicked, I want to check if its $(this).parent().siblings('.parent').child('.dropdown-toggle.active') so that I can untoggle them when another one is toggled. I know there isn't a child() selector, and I can't check siblings([selector])'s elements without an $.each or a loop, but I was wondering if there's a way? I want to use it in an if statement so I need it to be short and not heavy on processing.

Edit: Just ended up using $(this).parent().siblings('.parent').children('.active'). Thought siblings() would be an array and I'd have to iterate through it. Apparently it's an object and I could simply using children() on every element in the object.