ABAP has a function module named “RPY_FUNCTIONMODULE_READ” which lets you extract metadata about the function module. To be more precise, it lets you extract the parameter structure of function module and once you know the parameters then you can access them dynamically. But it comes at a cost, if you need to accomplish it, you should have S_DEVELOP authorizations permissions and it will be a performance intensive operation.
Another way round will be to add tracing or logging to function parameters manually.
In addition to this, ABAP has a utility class “CL_FB_FUNCTION_UTILITY” which has various methods. One of them is “METH_GET_INTERFACE” which to lets you extract parameters and corresponding data types of the function module.
You can choose either of them as per your convenience and applicability.