Final answer:
HR Topic Categories primarily group common HR Services to organize HR issues and help employees understand roles and services within an organization.
Step-by-step explanation:
The primary purpose of HR Topic Categories is to group common HR Services. These categories serve to organize and simplify the navigation of HR-related issues within an organization. By clustering services, employees can more easily discover employee roles and understand how these roles fit into the broader organizational structure. It also helps staff members to learn about the type of work others do, and how it intersects with their own responsibilities. For instance, the category of 'teachers' might further be broken down into sub-groups like 'teachers' unions', 'teachers who coach', or 'staff members involved with the PTA', which helps in identifying specific services or groups corresponding to certain professional interests or functions.