Creating a data category for each product and assigning data categories to service agents is an approach that can ensure that knowledge search only displays articles for a service agent's product specialization. Data categories are classifications that can be used to organize and filter knowledge articles by topic or type. Data category visibility can be set for each user profile or permission set to control which data categories are accessible for each user. Verified References: : https://help.salesforce.com/s/articleView?id=sf.
knowledge_categories_overview.htm&type=5 : https://help.salesforce.com/s/articleView?id=sf.
knowledge_categories_assign.htm&type=5