How to add a specific Hierarchy in OlapReport

  OlapReport olapReport = new OlapReport();

            olapReport.CurrentCubeName = "my_cube";

            //// Creating a dimension element object

            DimensionElement dimensiontElementProduct = new DimensionElement();

            dimensiontElementProduct.Name = "my_dim";

            dimensiontElementProduct.HierarchyName = "my_hierarchy";

            olapReport.SeriesElements.Add(new Item { ElementValue = dimensiontElementProduct });