Add the Supply filtering to other themes as a horizontal bar of dropdown lists. See the visual: http://snapify.shopify.com/30-15-45bo0-byoi2.jpg with the potential to be: http://snapify.shopify.com/30-50-v2h1u-wjtet.jpg

advanced-tag-loop.liquid

{% comment %}
  Create this snippet!
  
  A recursive loop to catch and filter out the different tag categories.
  This is mainly for advanced tagging, but will also help us strip
  out any tag categories from our tags (E.g. remove BRAND_ from BRAND_tag)
{% endcomment %}
{% if template contains 'collection' and collection.all_tags.size > 0 %}
  {% assign c = 0 %}
  {% for t in collection.all_tags %}
  {% capture cat %}{{ cat }}{% capture temp_cat %}{% if t contains '_' %}{% assign cat_grp = t | split: '_' %}{{ cat_grp.first }}{% endif %}{% endcapture %}{% unless cat contains temp_cat %}{% if t contains '_' %}{% assign new_cat_grp = t | split: '_' %}{{ new_cat_grp.first }}{% endif %}{% unless forloop.last %}+{% endunless %}{% assign c = c | plus: 1 %}{% endunless %}{% endcapture %}
  {% endfor %}
  {% assign cat_array = cat | split: '+' %}
{% endif %}

collection.liquid

<div style="width:100%;">
  {% if collection.all_tags.size > 0 %}
    {% include 'collection-tagbar' %}
  {% endif %}
</div>

new_gist_file_0

  {% include 'advanced-tag-loop' %}
  
  {% comment %}
    Loop through tag categories
  {% endcomment %}
  
  {% for cat_item in cat_array %}
    {% comment %}
      Ignore if tag category is empty
    {% endcomment %}
	{% unless cat_item == '' %}
	  <div class="browse-tags">
        <label>{{ cat_item }}</label>
        <select class="advanced-filters">
          {% comment %}
            Loop through collection tags
          {% endcomment %}
          <option value="">All</option>
          {% for custom_tag in collection.all_tags %}
            {% if custom_tag contains cat_item %}
              {% comment %}
                Strip out tag category prefix and add/remove link for tag filtering
              {% endcomment %}
          	  {% capture show_tag %}{{ custom_tag | remove: cat_item | remove: '_' }}{% endcapture %} 
              {% if current_tags contains custom_tag %}
                <option class="advanced-filter active-filter" value="{{ custom_tag | handle }}" data-group="{{ cat_item }}" selected="selected" data-handle="{{ custom_tag | handleize }}">{{ show_tag | strip | capitalize }}</option>
              {% else %}
                <option class="advanced-filter" value="{{ custom_tag | handle }}" data-group="{{ cat_item }}">{{ show_tag | strip | capitalize }}</option>
              {% endif %}
            {% endif %}
          {% endfor %}
        </select>
      </div>
    {% endunless %}
  {% endfor %}

    <script>
    /*$(function() {
      var currentTags = '{{ current_tags }}',
          filters = $('.advanced-filter'),
          activeTag,
          activeHandle;

      filters.each(function() {
        var el = $(this),
            group = el.data('group'),
            isActive = el.hasClass('active-filter');
      });

      filters.on('click', function(e) {
        var el = $(this),
            group = el.data('group'),
            url = el.find('a').attr('href');

        // Continue as normal if we're clicking on the active link
        if ( el.hasClass('active-filter') ) {
          return;
        }

        // Get active group link (unidentified if there isn't one)
        activeTag = $('.active-filter[data-group="'+ group +'"]');

        // If a tag from this group is already selected, remove it from the new tag's URL and continue
        if ( activeTag && activeTag.data('group') === group ) {
          e.preventDefault();
          activeHandle = activeTag.data('handle') + '+';

          // Create new URL without the currently active handle
          url = url.replace(activeHandle, '');

          window.location = url;
        }
      });
    });*/
    
var advancedFilters = jQuery('.advanced-filters');
  advancedFilters.change(function() {
      var newTags = [];
      var newURL = '';
      delete Shopify.queryParams.page;
      advancedFilters.each(function() { 
        if (jQuery(this).val()) {
          newTags.push(jQuery(this).val());
        }
      });
      {% if collection.handle %}
      newURL = '/collections/' + '{{ collection.handle }}';
      if (newTags.length) {
        newURL += '/' + newTags.join('+');
      }
      var search = jQuery.param(Shopify.queryParams);
      if (search.length) {
        newURL += '?' + search;
      }
      location.href = newURL;    
      {% else %}
      if (newTags.length) {
        Shopify.queryParams.constraint = newTags.join('+');        
      }
      else {
        delete Shopify.queryParams.constraint;
      }
      location.search = jQuery.param(Shopify.queryParams).replace(/\+/g, '%20');
      {% endif %}      
  });
</script>