A more thorough explanation:

in cursu diligentiae

In the process of carrying out a legal decision.

• The lawyer was required to provide evidence of in cursu diligentiae to show that they had followed through with the court's orders.
• The judge praised the defendant for their in cursu diligentiae in completing their community service hours on time.

These examples show how in cursu diligentiae is used in a legal context to refer to the actions taken to fulfill a court order or decision.