Final answer:
Finding good examples of 'third level navigation' is challenging because it complicates user experience and is only necessary for deeply categorized content. Designers often choose simpler navigation solutions to keep user interfaces intuitive. Exceptional third-level navigations exist but are specific to particular sites or applications.
Step-by-step explanation:
It is often hard to find good examples of 'third level navigation' because designing such navigational structures is complex and the need for them only arises in particular contexts. Most websites and applications strive to maintain simplicity in their navigation to enhance user experience. This means it's common to see top-level (main menu) and second-level navigation, but third-level navigation can lead to confusion, making the user experience more complex, potentially negative.
Moreover, the purpose of third-level navigation is to deeply categorize content, and not all websites or applications have content that requires this depth of categorization. When they do, designers often opt for alternative navigation elements such as filters, search functions, or expandable menus to avoid overwhelming users with too many choices.
With so many considerations to balance – such as clarity, user experience, and the amount of content – creating a useful third-level navigation can be quite a design challenge. Therefore, while some exemplary third-level navigations do exist, they are not as commonly showcased because they are tailored to specific needs and may not be as universally applicable as more standard navigation strategies.