I assume you are using CE2013 ?
it may be that the tutorial states this feature and we did not remove it in the 2013 version of the tutorials. actually, due to the complete rework of CE 2013 ( to implement the CityEngine SDK ), this feature had to be skipped for time reasons.
we're right now reimplementing it.
sorry for the inconvenience ..
Hmm. now I'm not sure if I understood you correct in the first place.
Can you post a screenshot of where you're missing the function ?
Let me know ..