The interviewer wants to know that you can think outside the box, or even ask for help when you are stuck on a complicated problem.
Maybe you look to a mentor or boss for advice. Perhaps you have handbooks, manuals and systems you turn to for help. Offer some relevant examples based on your industry. If you work in the medical field, you may turn to textbooks, online research, colleagues or even patient's history to find the right solution. If you work in customer service, you may ask the customer what they need to find the best way to solve the problem.
Show the interviewer that you are knowledgeable and equipped to handle these types of scenarios.
"When faced with a complicated problem, I will look to the resources that my current company has provided me. The answer is almost always in there. If it's more of a moral dilemma vs. a knowledge-based dilemma, I will ask my supervisor for his thoughts and opinion since I value him as a mentor and expert in our industry."
"To solve a complex issue, I will reach out to a manager or mentor from a previous role to ask them how they've handled such issues in the past. I am always ready to dive back into our handbook, but these types of scenarios are often not covered there, which is why I value a human, experiential approach. I know that there are so many folks in the industry who have so much to teach me and have probably already "been-there-done-that," so I love to utilize them as a resource."