DRC configuration - create Tax Group - how to add Tax Rate field as a parameter?

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Version: SAP S/4 HANA On-Premise

Question: DRC configuration question - how to enhance the configuration table of Tax Group to add Tax Rate column? What other impact does it have by adding Tax Rate into this definition of Tax Group?

Tax Rate is required to differentiate the Tax Groups (and subsequently map to different Tax Boxes). 

e.g. DE VAT Return 

Tax Code DA - 19% => mapped to Tax Group 81 (Tax Box 81)

Tax Code DA - 16% => mapped to Tax Group 35 (Tax Box 35)

The background is that tax code remains the same one DA for the VAT rate change from 19% to 16% using a third party time-dependent tax code solution (not SAP TDT solution as it is not available yet in On-Premise).