4channel dimmer pack

I have a 4 channel dimmer pack to control par cans. I created a custom device and used 4 dimmer controls (intensity) for the 4 channels. But when I assign this device to a group, I only have one dimmer control, not 4. What am I not understanding?
Is the only way to do this to create 4 devices with 1 channel each?


Yes I have same dmx fixture too
A 4 channels outlet with dimming
I created one device named Sub 4 channels outlet and I mapped this 4 times