Need another help from LS-master.
I am using the question type Array Dual Scale. First scale is yes/no and 2nd scale is the rating, which suppose to be only for who answer yes at 1st scale.
Or if answer no, directly only N/A available at 2nd scale. Possible?

Anybody can help show me how to define the condition for such case?


Many thanks in advance.

That's not what the dual scale question was designed for and therefor this isn't possible.

Try the following:
Instead of using yes/no change your question text like "Please tick the items which you like to rate". Then use a multiple option question.
At a following array question create your own ratings and make use of the array filter question attribute. This way only items ticked previously will be shown at the following ratig question.