  {% assign _section_id = _section.id %}
              {% unless _section_id %}{% assign _section_id = 'nav-' | append: forloop.index %}{% endunless %}
            <button class="bc-accordion-button bc-nav-link" aria-expanded="false" aria-controls="{{ _section_id }}">
              <span>{{ _section.text }}</span>
            </button>
            {% if header.type == 'basic' or header.type == 'extended' %}
            <ul id="{{ _section_id }}" class="bc-nav-submenu" aria-hidden="true">
            {% endi