Mixing hierarchical and flattened stacking

You can use the descriptionGroup option to combine hierarchical and stacked flattening in one diagram. This example uses hierarchical layout for top-level groups and flattens lower-level groups.

Since setting per-group stacking is not yet supported, to implement flattened stacking inside a hierarchical layout a small trick is required: all groups on the second level have their open and description properties set to true. This will visually emulate flattened stacking while the global stacking option remains set to hierarchical.