The value of this property defaults to true.
When set to true, a level is generated for each HierarchyDescriptor which represents all members of that level. The resulting hierarchy displays expandable row/column headers, which group subsequent levels.
Target Platforms: Windows 10, Windows 8.1, Windows 8, Windows 7, Windows Server 2012, Windows 7, Windows Vista SP1 or later, Windows XP SP3, Windows Server 2008 (Server Core not supported), Windows Server 2008 R2 (Server Core supported with SP1 or later), Windows Server 2003 SP2