To synchronize the hierarchy between BW and SEM-BCS use program UGMDSY20, so BW hierarchies become available for SEM-BCS.

Or, if you load the hierarchy through flex-upload in SEM-BCS, then hierarchy becomes available in both SEM-BCS and BW.

However, in practice SEM-BCS projects utilize BW implementation in exist, and UGMDSY20 is for that.

* Quoted from a thread in IT ToolsBox, thanks to Metin Colak.

* You also can find a How-to guide of "How To Upload Hierarchy and Master Data of FS Items in SAP SEM-BCS 4.0 by Using Flexible Upload Method" in SAP SDN, contributed by Eugene Khusainov.