Not sure what you expect. Maintenance via RFC means that you have a program in the target system that is called by a program from the source system.
You goal is to update the product hierarchy in the target system, so your caller program has to submit the relevant data to the program in the target system which has its input parameters/tables to receive those submitted data and this program can then create the wanted hierarchy.
Both programs are Z programs and have to be developed by your ABAP team.