core/Templating/templates/renderer/sections-subtabs.twig
<div id="{{ section.uid }}" data-kbfsubtabs class="kbf-subtabs-container">
<div class="kbf-fields-tabnav">
<ul>
{% for tab in section.tabs %}
{% if tab.hasVisibleFields() %}
<li><a href="#tab-{{ tab.getId() }}">{{ tab.getLabel() }}</a></li>
{% endif %}
{% endfor %}
</ul>
</div>
<div class="kbf-fields-tabscontainer">
{% for tab in section.tabs %}
<div id="tab-{{ tab.getId() }}">
{% for field in tab.fields %}
{% if field.isVisible() == true %}
{{ field.render() }}
{% endif %}
{% endfor %}
</div>
{% endfor %}
</div>
</div>