What is Multiple-Hierarchy?Aggregate Storage Database can have multiple hierarchies within dimension. That is 'Stored' and 'Dynamic' hierarchies.

First you have to enable Multiple-hierarchy at the dimension level.

Multiple hierarchies are irrelavant in BSO world. Oracle is trying to bring together BSO and ASO functions in-sync while without loosing much performance to ASO world. Because of that, there are many restrictions on the hierarchy definitions and properties. I expect to see some of those restrictions go away in the future releases.
Stored Hierarchy- Stored Hierarchies are aggregated rather than calculated.
- Stored hierarchies can have ~ or + consolidation operators
- Stored hieraries CANNOT have formulas
- Stored hierarchy dimensions cannot have shared members, but stored hierarchies within multiple hierarchies can have shared members.
Dynamic Hierarchy- Dynamic Hierarchy values are calculated instead of aggregated and stored at the time of retrieval.
- Dynamic hierarchies can have any consolidation operator (+, -, *, /, %, ~).
- Can have member formulas (="jan" + "feb" + "mar";)
- Essbase cannot select dynamic hierarchy members for an aggregate view.
In BSO outline, it does not matter whether the parent member (YTD-09) is dynamic or stored. If Dynamic it calculates the value in retrieval.
Here is a screen shot in BSO. Both outline works fine with or without dynamic property.

