By using RadPivotFieldList, the end user can change the way of representing aggregated data in RadPivotGrid by modifying the column/row group descriptions, the aggregate descriptions or the report filters. The end users can do this by dragging fields across the four list boxes in RadPivotFieldList or by reordering the items in a single list. This functionality is achieved by the PivotFieldListDragDropService.
Similar to RadDragDropService, PivotFieldListDragDropService exposes public events which allows to handle the drag and drop operation and customize it according to your requirements, e.g. control which items to be dragged.