@maidus – I wasn’t able to get the query for ACF select values to work, so I ended up doing custom taxonomies added to the post type, then doing individual queries for each. Was using this for populating the Isotope jQuery plugin for filtering products.
<?php $headstyles = get_categories('taxonomy=mag_filter&post_type=product'); ?>
<?php foreach ($headstyles as $headstyle) : ?>
<div class="option" data-filter=".<?php echo $headstyle->slug; ?>"><?php echo $headstyle->name; ?></div>
<?php endforeach; ?>
