How to expand only the current position of a selected member in the OlapReport

 
 
  private OlapReport CreateOlapReport()
        {
            OlapReport olapReport = new OlapReport();
            olapReport.CurrentCubeName = "Adventure Works";
 
            DimensionElement dimensionElement = new DimensionElement() { Name = "Customer", HierarchyName = "Customer" };
            dimensionElement.AddLevel("Customer Geography", "Country");
            olapReport.SeriesElements.Add(dimensionElement);
 
 
            dimensionElement = new DimensionElement() { Name = "Geography", HierarchyName = "Geography" };
            dimensionElement.AddLevel("Geography", "Country");
            olapReport.SeriesElements.Add(dimensionElement);
 
 
            dimensionElement = new DimensionElement() { Name = "Date" };
            dimensionElement.AddLevel("Fiscal", "Fiscal Year");
            olapReport.CategoricalElements.Add(dimensionElement);
 
            olapReport.DrillType = DrillType.DrillPosition;
 
            return olapReport;
 
        }