Shopify product breadcrumbs showing tag-based subcategories. Full tutorial here: http://zoerooney.com/blog/tutorials/shopify-product-breadcrumbs-with-tag-support/

breadcrumbs.liquid

<div class="breadcrumbs">
    <a href="/" class="homepage-link">Home</a>
    {% if collection.handle %}
         &gt; 
        {% capture url %}/collections/{{ collection.handle }}{% endcapture %}
        <a href="{{ collection.url }}" class="collection-link">{{ collection.title }}</a>
    {% endif %}
    <span class="bc-tags"></span><!-- this is a placeholder for the tag if there is one -->
</div> <!-- end .breadcrumbs -->

<script>
    // get URL parameter (added in the grid link)
    tag = window.location.search.substring(1).split("=")[1];
  
    jQuery(document).ready(function($){
        // get the active menu item (the top level item)'s text - could be different than the collection title
        // if you might have more than one active item in your nav structure, you may need to be more specific
        var parent = $('.active').text();
        
        // update the displayed collection title to match the nav item label
        $('.collection-link').text(parent);
        
        // check if there's a URL parameter for the tag
        if ( tag ) {
            console.log(tag); // output it in console for debugging
            
            // find the nav item for this tag using the data attribute for the slug
            var tagElement = $('a[data-tag-slug="' + tag + '"]');
            
            // get the display name from the other data attribute
            var tagname = tagElement.data('tag-name');
            
            // output the tag link in the placeholder area
            $('.bc-tags').html(' &gt; <a href="/{{ collection.url }}/' + tag + '">' + tagname + '</a>');
        } else {
            // output a message to console if there's no parameter, for debugging
            console.log('sorry, no tag parameter here');
        }
    });
</script>

grid-link.liquid

<a href="{{ product.url | within: collection }}{% if current_tags %}?tag={{ current_tags.first | handleize }}{% endif %}">
    <img src="{{ product.featured_image | product_img_url:'grande' }}" alt="{{ product.title }}" id="img{{ img_count }}" class="main-img" />
    <h3>{{ product.title }}</h3>
</a>

navigation.liquid

<ul>
    {% for link in linklists.main-menu.links %}
        {% assign handle = link.title | handle %}
        <li>
            <a{% if link.active %} class="active"{% endif %} href="{{ link.url }}">{{ link.title }}</a>
            {% if linklists[handle].links.size > 0 %}
		<ul class="child">
                    {% assign parenthandle = link.url | remove: '/collections/' %}
		    {% for link in linklists[handle].links %}
		        <li>
			    <a href="{{ link.url }}" data-tag-slug="{{ link.url | remove: '/collections/' | remove: parenthandle | remove: '/' }}" data-tag-name="{{ link.title }}" >
			        {{ link.title }}
			    </a>
	                </li>
		    {% endfor %}
                </ul> <!-- end .child -->
	    {% endif %}
	</li>
    {% endfor %}
</ul>

Hi Zoe.

Nice resource. Just to a quick note to say that your blog/tutorials link is down!!

Bump! Tutorial link is still down. 👍