The 5G layer-2 include MAC, RLC and PDCP . The 5G layer-3 is RRC layer as shown in 5G protocol stack. The Figure-1 depicts 5G Protocol Stack consisting of both User Plane and Control Plane protocol layers.
PDCP is located in the Radio Protocol Stack in the UMTS/LTE/5G air interface on top of the RLC layer . PDCP provides its services to the RRC and user plane upper layers, e.g. IP at the UE or to the relay at the base station.