This seems like a ladder of abstraction on the subject of moral judgment:
The Golden Rule ("do unto others as you would have them do unto you") — refers to acts and preferences over acts
Matthew 7:2 ("you will be judged in the same way that you judge others, and the measure that you use for others will be used to measure you") — refers to judgments of acts and preferences over such judgments
The Categorical Imperative ("act according to the maxim whereby you can at the same time will that it should become a universal law") — refers to rules generating acts (including judgments) and preferences over such rules
If there's a fourth step on this ladder, it might be something like "Create agents capable of climbing this ladder" or "Create a world in which you and others can proceed up this ladder".