https://blogs.sap.com/2013/10/21/custom-hierarchies/
https://blogs.sap.com/2012/05/02/custom-hierarchy-extraction-in-sap-bw-73-part1/
https://blogs.sap.com/2012/08/09/custom-hierarchy-extraction-in-sap-bw-73-part2/
https://blogs.sap.com/2012/08/10/custom-hierarchy-extraction-in-sap-bw-73-part3/
