head_tag.html

<script type="text/discourse-plugin" version="0.8.18">

  var nmlt = settings.Nav_links,
    sec = $.map(nmlt.split("|"), $.trim);

  $.each(sec, function(value) {
    var sec = $.map(this.split(";"), $.trim),
      filter = sec[0].replace(/\s+/g, "-").toLowerCase(),
      location = sec[2];

    api.addNavigationBarItem({
      name: filter,
      displayName: sec[0],
      title: sec[1],
      href: sec[2]
    });

    api.modifyClass("component:navigation-item", {
      pluginId: 'discourse-nav-links-component',
      active: Ember.computed("contentFilterMode", "filterMode", function() {
        let contentFilterMode = this.get("content").get("filterMode");

        if (window.location.pathname === location) {
          return contentFilterMode === filter;
        } else {
          return this._super(contentFilterMode, this.get("filterMode"));
        }
      })
    });
  });
</script>