The interviewer is looking for answers to a few points when asking this question.
1. The company wants to know what kind of timeline is present before you are scooped up by another organization.
2. They want to know how discerning you are with your job applications.
3. They want to know the types of roles that interest you.
4. They want to hear that they are your top choice.
You can certainly discuss your search but avoid giving too many details. Give the interviewer enough to satisfy the question without revealing your entire search. Some mystery is okay here.
