There is a 3-part structure of information within Stratum.Viewer 
 that includes dimensions, 
 hierarchies, and levels. Hierarchies 
 belong to dimensions and contain at least one level, which in turn contain 
 members. You can see an example of 
 this structure in view explorer. In the following example, there is a 
 Product Family hierarchy (
) with a Product Family level 
 (
) in the rows. The hierarchy belongs 
 to a Product Family dimension, which you can see when you access the Properties 
 window for the hierarchy.
