I have attached a coloured wiring image from the Clymer manual (CB750 K6) which indicates..!..sorry...left,1 + left,2 & right,1 + right,2 (brown/blue=buzzer circuit)
The 1st position will operate the indicators, the 2nd position operates the indicators & buzzer. (I have a K4 and it's not fitted with this type of switch)
As previous post, the K2 (USA) version did have a lower push switch to omit the buzzer, and the throttle friction adjuster was discontinued after K4.