Cinema 4D Basic Features Create Menu Field Modifier Layers
Function available in CINEMA 4D Prime, Visualize, Broadcast, Studio & BodyPaint 3D

Python

Layer

Python

The Python Field Layer can be used to access the values of other Layers or modify the Python script language (see also http://developers.maxon.net; look for the Python Field object).

How this differs from the Python Field can be read here.