Next generation fronthaul interface has been recently proposed to support different functional splits in 5G access networks. Each split option is characterized by different requirements in terms of latency and bandwidth. The mapping of different functional splits on the nodes of 5G access network introduces several degrees of freedom in relation to the variation of the traffic during the day. This paper proposes a novel function location algorithm, which adopts dynamic function chaining in relation to the evolution of the traffic estimate. The obtained results show remarkable improvement in terms of bandwidth saving and multiplexing gain with respect to conventional C-RAN fronthaul and suggest design criteria for the emerging 5G access network.