Dear Franz,
Regarding to the Hierarchies in Business Object -
Report Based Hierarchy (Default Hierarchy): is Based on the Order in which Dimensions are placed in the Class within the Universe.
e.g.
In this case, when User perform Drilling on the report, user will be able to drill on Dimension accodring to the above Order in the Universe.
Drill Path: Year -> Year_Half -> Quarter -> Month
This drill path is defaulted in the report according to order in the universe.
In some cases when user want to drill directly from "Year Dimension" to "Quarter Dimension" and they don't want to passthrough the "Year Half Dimension". In this case, we can use "Custom Hierarchy".
Custom Hierarchy: is used when two or more hierarchies starts with Same Dimensions but follow by different dimensions at lower end.
You can defind Customer Hierarchy in Universe Deisgner by selecting "Tools > Hierarchies" as shown in following figure.
In this case you can define "Custom Hierarchies" as follow:
By defining "Custom Hierarchies" in Universe, you don't need to create a New Class with Different Dimension Hierarychy which may lead to Complexity of Universe. More efficient way to solve when different drill-paths are required for one Class in Universe.
When user peform drilling in report, Business Objects will prompt to choose the drill-path as shown in following figure:
Hope Helpful.
Best Regards,
Han. 