You can add the driving instance(s) for an instance, a net, or an input pin to a cone.
To add the driver of an instance to a cone:
In the NetlistViewer or a Logical Cone window, select the instance, net, or input pin whose driver you want to add to the cone.
Right-click the selected instance, and choose Add To Active Cone>Add Driver.
The driver for the selected instance appears in the active cone. For input pins, this command adds the connected net and driving instance to the active cone. For nets, this command adds the driving instance to the active cone. For each instance, this command adds the driver for each of the instance’s input pins to the active cone.
If the added objects can be connected to other objects already present in the active cone, this command also connects those objects.