_TUSB_HUB_H_ macro
Like most PC's OS, Hub support is completely hidden from Application. In fact, application cannot determine whether a device is mounted directly via roothub or via a hub's port. All Hub-related procedures are performed and managed by tinyusb stack. Unless you are trying to develop the stack itself, there are nothing else can be used by Application.
Notes
Due to my laziness, only 1-level of Hub is supported. In other way, the stack cannot mount a hub via another hub.