That's a power Darlington with an internal diode and two internal resistors. I'd just test them individually (if I couldn’t test them in-circuit). There should be a difference if one or more is bad.
From the emitter to collector, there is a protection diode. With high on the emitter and low on the collector a meter should read a forward diode junction. It should read open the other way around.
From the base to the emitter, there are two base to emitter junctions, but there is also about 115 Ohms in parallel with that. It will read low both ways (unless testing with high current, which I don’t think is necessary).
From the base to the collector, the path goes through the base to collector junction of the first transistor, but there is also the two resistors and protection diode that are in parallel with it. There should be a reading forward and it should be open reversed.
Again, I’d compare the readings to a known good one.