3621245 - Reference Base Mapping in Top-Down Distribution - SAP S/4HANA Cloud Public Edition

Need to know the efficient way to maintain Reference Base Mapping in TDD. 

SAP S/4HANA Cloud Public Edition

As introduced in Top-Down Distribution Cycle Segment | SAP Help Portal, Ref base mapping is used to build mapping relationship between sender and reference data for those Retained and Relevant to Reference characteristic fields whose sender data is different from reference data.
There is no need to maintain ref base mapping if the sender data is the same as reference data. 
All values to All values mapping is more efficient than other value types in reference base mapping. 

Make sure the same value for all relevant fields for sender basis and receiver basis so that TDD will work properly. 
If it's difficult to keep the same value, maintain 'All values' in the reference base mappings for these fields. 
The custom fields follow the same logic as above. 

Top-Down Distribution, TDD, Reference Base Mapping, Ref base mapping, Retained and Relevant to Reference, reference data, All values , KBA , CO-PA-2CL , Profitability Analysis (Public Cloud) , Problem