According to one embodiment of the present invention, a method performed by a first network repository function (NRF) entity in a serving public land mobile network (PLMN) is provided, the method comprising: receiving, from a requesting session management network function (SM NF) in the serving PLMN, a first NF discovery request message including an identifier of a home PLMN, agreed network slice assistance information, and a data network name; transmitting, to a second NRF entity in the home PLMN, a second NF discovery request message including the agreed network slice assistance information, and the data network name based on the identifier of the home PLMN; as a response to the second NF discovery request message, receiving, from the second NRF entity, an address of a target SM NF in the home PLMN; and transmitting, to the requesting SM NF, the address of the target SM NF.