There is an air intake control on the bottom of the chargrill side that can be used to regulate air flow. The only way you can "maybe" smoke on it would be to smoke on it like you would on a
weber kettle, that is, use a charcoal basket set to one side and the minion method (using charcoal) with some wood chunks or maybe a small split.
The way the chargrill side is made, the bottom grill is awful close to the coals. So you're going to have to use charcoal offset to the far side away from the meat.
There is now way of doing air flow control at the top chimney, but maybe try running with that wide open and controlling your air intake on the bottom while also just limiting fore fuel, aka charcoal briquettes. My guess is if you damped the air flow at the top of the stack, you'll end up with some pretty sooty food.
Just a thought and suggestion. I'm guessing you can do it with some practice but never get the same results as you would on the smoker side.
I have a 36 hybrid, and honestly if I had it to do again, I'd just get a 48, non-hybrid and a
weber kettle. I really like the 36 hybrid, but i don't find the chargrill side of things that much better than a
weber kettle. And, at times I wished I had more capacity one the smoker side.
All in all still a great smoker. Just next time, I'm going with the 48.