Explanation
Creating a data category for each product and assigning data categories to service agents is the recommended approach to ensure that Knowledge searches only display articles for a service agent's product specialization.
Data categories are a way of classifying articles based on topics or criteria that make sense for your business.
Data categories can be used to control the visibility and searchability of articles for different users and communities. By creating a data category for each product, you can group articles by product line and make it easier for agents and customers to find relevant information. By assigning data categories to service agents, you can restrict their access and search results to only the articles that match their product specialization.
Verified References: Service Cloud Consultant Certification Guide & Tips, Data Categories Overview