Yep - put the screen into Track mode and it will appear when you toggle through with the upper toggle switch. From the manual:
Menu 1: LEAN ANGLE
The LEAN ANGLE function is only available for the displaying with the standard screen in TRACK mode.The information about the LEAN ANGLE function, if active, is available under Menu 1. Thanks to the LEAN ANGLE function, the instrument panel can display the real-time lean angle of the motorcycle. Negative reading corresponds to lean angle on the left (from
riding position) and positive reading corresponds to lean angle on the right.
Note
The TRIP FUEL function always has top priority over the LEAN ANGLE function: in case of activation of the TRIP FUEL function with active LEAN ANGLE function, the LEAN ANGLE view is automatically removed and TRIP FUEL information is displayed instead.