What button is being used to change between the 3 panel displays?

The Navigation View Button is the appropriate choice for changing between the three panel displays in the Global Combat Support System (GCSS) Army interface. This button is specifically designed to allow users to navigate through different views or panels seamlessly, enhancing user interaction with the system. It is important in operational scenarios where efficient access to various segments of information is critical for decision-making and resource management.

While the other options might seem relevant in a different context, they do not accurately represent the function of switching between panel displays in GCSS. The Navigation View Button is directly tied to user interface transitions that facilitate quick changes and better visibility of the data required for effective unit supply operations. Familiarizing oneself with this feature is essential for any personnel involved in logistical operations within the GCSS framework.