That sounds very much like the programming menu of a stock ESC.
You get into the programming menu the same way you start calibration: ESC signal (throttle) to 100% high and then plug power into the ESC.
The ESC do it's first beep. If you immediately set ESC signal to 0% you have just calibrated the ESC.
If you wait, you get the programming menu. If you hear for instance 2 beeps and then set ESC signal to 0%, you have entered option #2 which may be something like brake or soft start or such. You will get 1 beep, pause, 2 beeps, pause, 3 beeps, etc.