I need to target a specific div in Shopify. I'm using Boundless Theme. I want to add a custom id attribute to this specific div. How can I do this?

The div I need to target is the 3rd div with class "product-item grid\_\_item medium-up--one-third":

```
<div class="featured-collection" data-section-id="featured-collection" data-section-type="featured-collection-section">

    <h2 class="visually-hidden">frontpage</h2>

    <div class="grid grid--no-gutters grid--uniform collection-grid">

        <div class="product-item grid__item medium-up--one-third">

            <a class="product-item__link " href="/products/kaylava-candor-decaf-coffee-bean">

                <img class="product-item__image" src="//cdn.shopify.com/s/files/1/1460/5816/products/candor-coffee-sm_grande.jpg?v=1485668871" alt="CANDOR DECAF COFFEE">

                <span class="product-item__meta">
                <span class="product-item__meta__inner">
                <p class="product-item__title">CANDOR DECAF COFFEE</p>
                <p class="product-item__price-wrapper"><span class="txt--emphasis">from</span> $15.99</p>
                </span>
                </span>

                </a>
        </div>

    </div>

</div>

```