I beleive this is incorrect. According to the manual, the top adjustment is left/right bias. It controls how fast the heli rotates left or right with a given amount of stick input. This is used so it doesn't rotate left faster than right or vice versa.

The middle is gyro gain. Used to eliminate tail wag. If it wags, reduce the setting by turning counterclockwise.

The bottom is trim. If the heli still rotates left or right with the trim setting on the transmitter all the way over, here is where additional adjustments can be made.

There is no adjustment for pitch on the 3in1. Those are made at the transmitter, or through adjusting the lengths of the connecting rods.