This enhancement is a part of the February 19, 2022 release.
Customers with Department Headers enabled on their Central website can now find Department and DepartmentID data as Custom Dimensions in Google Analytics. Child pages of a designated Department Header will show the Department Header page title in the Department custom dimension and page id in the DepartmentID.
These custom dimensions will allow analytics users to build reports and analyze data for web traffic within that particular section of their website. For more information, visit Google to learn more about Custom Dimensions in Google Analytics.