As of version 2502, the default standard hierarchy changes for new cost centers.
Before version 2502, when you created a new cost center, it used to be assigned to standard hierarchy 0001 by default, which is a hierarchy based on a set of cost center groups.
With version 2502, the default behavior changes:
If you don't have existing cost centers created in previous versions, new cost centers you create are assigned to a newly created global hierarchy with the topmost standard hierarchy node 1.
To view this standard hierarchy, use the Manage Global Hierarchies app.
If you do have existing cost centers, all new cost centers you create continue to be assigned to standard hierarchy 0001 by default, just as the existing cost centers.
You can also move the existing cost centers to the new global hierarchy, if needed. For details, see How to Migrate Cost Center Groups to Global Hierarchies.
The error "0001 is reserved for standard cost center group. Specify a different ID." will be triggered when creating cost center group 0001. If 0001 is required as the cost center group, it is recommended to follow 3594285 - Error "0001 is reserved for standard cost center group. Specify a different ID." - SAP S/4... to create it in the Manage Global Hierarchy app under standard hierarchy node 1 as a subnode.
Furthermore, Set Report Relevancy app & Replicate Runtime Hierarchy are needed for old SET groups, e.g., manage cost center groups, manage profit center groups. For hierarchies in Manage Global Hierarchy app, those steps are not needed. They can be used in analytical reports after activated in Manage Global Hierarchy. If you want to use them as SET Groups like cost center groups, set flag for corresponding hierarchy which is set ‘X’ for standard cost center hierarchy by default.
Details can be checked in below Help Portal links:
Cost Center Standard Hierarchy | SAP Help Portal
Set-Based Groups versus Global Hierarchies | SAP Help Portal
