The Chief Complaint (CC) is not being deleted or replaced. However, when a new template is layered, additional CC/HPIs are coupled together and added to the Encounter. A toggle located in the HPI section of the Encounter is used to move forward and backward through all CC/HPIs that have been added. The ROS section remains the same throughout the layering so that there is one comprehensive Review of Systems attached to the Visit.
In the animation below, you will see Sore Throat being entered as the first CC, and then Ear Pain layered on top of it. You will also see the toggle count increase to two and the use of the forward and backward arrows.