Apple TV Human Interface Guidelines
Very well put together. Worth your time both to better understand the new Apple TV interface as well as brush up on some universal principles like this on Navigation:
People tend to be unaware of an app’s navigation until it doesn’t meet their expectations. Your job is to implement navigation in a way that supports the structure and purpose of your app without calling attention to itself. Navigation should feel natural and familiar, and shouldn’t dominate the user interface or draw focus away from content.