Currently, you have ColumnGroupsDefaultExpanded and RowGroupsDefaultExpanded available for the PivotGrid.

I would like to request an ExpandedGroupsBehavior that allows you to set a particular level to expand to.

To better explain this, the WPF PivotGrid has this. Here is a the documentation: http://docs.telerik.com/devtools/wpf/controls/radpivotgrid/features/expand-behavior.html

Thank you