How to create hierarchy in SAP BW

Before you can create a hierarchy for an infoobject, say cost center, you must first ensure that the infoobject supports hierarchy. So in the infoobject change screen, choose the hierarchy tab and select "with hierarchies":



Save/Activate etc usual stuff. Now, go back to the infobject catalog directory, right click on the infoobject and choose create hierarchy:



And walla. You'll get to the hierachy screen, and can add nodes and such. But to make things much easier, I recommend using flat files upload to load your hierachy from excel.