This panel is exclusive to Cinema 4D and part of the shader. It provides functions and parameters to fine-tune the appearance of the underlying geometry. These features are exactly the same as in Cinema 4D's native materials. There you can find a “Displacement” channel to adjust and control the sub-polygon displacement properties. With sub-polygon displacement you are able to achieve highly-detailed ocean surfaces and enhance mapping. Please be aware that this feature also requires a map with an appropriate level of detail. You can change the quality of the statistical spectrum waves with the “Quality” parameter in RealFlow.
For a description of the shader's “Displacement” parameters and options, please take a look at Cinema 4D's manual. There, the required information can be found under:
Material Manager > Material Properties > Displacement
The "Displacement" tab in Cinema 4D.