I've created an additional details page with a duplicate of the dropdown menu for testing. Use only the Gear Lubricants tab.
Starting with the original url (PM), the Greases tab should be active (red). When you click on Gear Lubricants, it should turn red (not white), and become the active tab. When a product is selected from the Gear Lubricants dropdown menu, it redirects to a detail page. The Gear Lubricants tab should be red there as well (it uses the same dropdown menu).