Using a fruit tree as an easier to visualize analogy will explain the concept of this hierarchy better, the trunk of the tree is the Group (Serum Chemistry), the fruit bearing branch is the actual order, Procedure Order (Serum Uric acid) and the fruit is the result, Discrete Result, also called (Serum Uric Acid) that will hold the value of the returned result. Just as the fruit is not borne on the main trunk you should not place a Discrete Result as a direct descendant or child of a Top Group. Similarly the fruit bearing branch (Procedure Order) cannot be placed as a direct descendant or child of a fruit (Discrete Result)