Ok, you haven’t added id=“product-nav” to the dropdown and there was a typo on this line.
var $el = $(event.target).closest(a);
Use this script instead.
<script>
$('#product-nav').on('click', 'a', function(event) {
event.preventDefault();
var $el = $(event.target).closest('a');
var hash = $el.attr('href').split('#')[1];
$('a[href="#' + hash + '"]').tab('show');
})
</script>
These sections were only for explaining how the script worked, they don’t need to be included.
$('a[href="#minisonic"]').tab('show')
$('a[href="#sonictravel"]').tab('show')