This level of architecture is defined in the common approach to Federal Enterprise Architecture Framework and focuses on a particular service area or business unit within an agency or between agencies that is not Federal-, Sector-, or Agency-wide. Each segment is defined either organizationally (e.g., as a business unit and per the organization chart) or functionally (as a vertical or crosscutting mission or support service).

Source: See Federal Enterprise Architecture Framework (common approach - as explained in Collaborative Planning Methodology).

Alongside the breadcrumbs for this item which shows its "ancestry" in concept space, the Child items tab lists its descendants, and the Siblings items tab the concepts that exist under the item's "parent item".