When you go to the grocery store, you are not just doing business with the produce department, but the entire store.  As a consumer, if I want to know where capers are in the store, I am going to look for the first employee I see and ask for the location of the capers. My expectation is that they will tell me, not only the number of the aisle, but also the location in the aisle. Even better than that, walking me to the capers is the best customer experience they can provide! 

All businesses need to speak a very consistent message to their employees on the expectation of assisting customers. You may work "in a department," but you work "for the company."  No one knows all the answers to the questions asked by customers, but it's your job to make sure the customer is not left fending for themselves in finding what they need.