[BR-47-GST-SG]-Each GST Breakdown (BG-23-GST) shall be defined through a GST category code (BT-118-GST).
BR-47-GST-SG
cac:TaxTotal/cac:TaxSubtotal
exists(cac:TaxCategory[cac:TaxScheme/cbc:ID='GST']/cbc:ID)