search_filter_partial - size only

search_filter_partial_size_only.html

<h4>Size</h4> 
  {% set option_values = category ? my_cat.list_unique_product_option_values('Size') : method('Shop_CustomAttribute','list_unique_values','Size') %}
  {% set selected_size = selected_options['Size'] ? selected_options['Size'] : [] %}

  <input type="hidden" name="option_names[]" value="Size"/>
  <select style="display:none" id="size-select" class="search-filter-select" name="option_values[]">
    <option value=""><strong>Choose Size</strong></option>
    {% for value in option_values %}
      <option
        {{ option_state(value, attribute(selected_options, 'Size')) }}
        value="{{ value }}">{{ value }}</option>
    {% endfor %}
  </select>
  	{% for value in option_values %}
  		<span id="{{value}}" data-value="{{value}}" data-select="size-select" {{ selected_size == value ? 'class="filter-option size-option search-filter-selection"' : 'class="filter-option size-option"' }}>{{value}}</span>
    {% endfor %}