IGameInputReading::GetSystemButtonState

bool GetSystemButtonState(
    GameInputSystemButtons* buttons
);

Microsoft::WRL::ComPtr<IGameInput> gameInput;
GameInputSystemButtons previousButtons = GameInputSystemButtonNone;

void PollGuideButton() noexcept
{
    Microsoft::WRL::ComPtr<IGameInputReading> reading;
    if (SUCCEEDED(gameInput->GetCurrentReading(GameInputKindSystemButton, nullptr, &reading)))
    {
        GameInputSystemButtons buttons = GameInputSystemButtonNone;
        if (reading->GetSystemButtonState(&buttons))
        {
            const bool guidePressed = (buttons & GameInputSystemButtonGuide) != 0;
            const bool guidePreviouslyPressed = (previousButtons & GameInputSystemButtonGuide) != 0;
            if (guidePressed && !guidePreviouslyPressed)
            {
                // Handle new Guide button press
            }

            previousButtons = buttons;
        }
    }
}