Ah. Different equipment uses different markings for various wires.
To find out which sensor is HB, trace the wire from the HB wire to the sensor it connects to. If you've removed the wires, then trace from the HB pad, if you know which one that is.
If you have a multimeter with either 2ohms range or continuity, set it to either of those, black probe in Common/GND, red probe in V/Ohms, and connect black probe to the HB wire, and use the red probe to touch each of the hall sensor pins exposed on the face of that board. If in continuity, the one that beeps is the HB hall. If in 2ohms, then it'll show something close to 0 for the HB hall, and probably OL for the others.