Does anyone know if there is a way to manipulate a hierarchy during upload. I'm looking for something like transferrules where I can add/delete some data.
create a "loop" within BW.
Mark the InfoObject as InfoProvider, then you can use it as ExportDataSource and generate export dataSources.
Create updaterules for hierarchies on the myself-system on datasource 8<full InfoObjectName like 0MATERIAL>H.
Do not forget to replicate the DataSources for the myself sourcesystem.
now go to CMOD in the BW-System, create your Projet for Exit RSAP0001 and now use the _004-Exit within BW.
Here you can do all the nasty things about your hierarchy.
The first upload the original, afterwards upload the change to it within BW.
Keep in mind that it might be advisable to rename your hierarchy during upload, to be able to check the differences.