level
 Hierarchies can have different numbers of levels. For example, a Product
    hierarchy containing All Products, Product Groups, Product Sub-groups and Products is a
    four-level hierarchy. A Time hierarchy containing Year, Quarter, Month, Week and Day is a
    five-level hierarchy. In the list designer you can specify that only list elements at a
    particular level of the hierarchy are displayed (for example, only product sub-groups). In the
    List Designer in Application Studio you can specify the level by its name.
    Levels also have numerical identities. The parent or root level of a hierarchy is at Level 1 and
    the levels and sub-levels are Level 2, Level 3 etc.