While in generic mode, the RFC Input Adapter can invoke multiple RFCs in sequence. This is called RFC chaining.
The RFCs are invoked in the order specified in the adapter configuration file. In the mapping file, you can set the output of an RFC as the input to a subsequent RFC. You can only do this if the data types of these parameters match, meaning they must both be structure or table parameters with the same line definition or have a compatible underlying ABAP type.