A hard x-ray self-seeding (HXRSS) setup will soon be available at the European X-ray Free Electron Laser (XFEL). The availability of high repetition rate x-ray pulses poses novel challenges in the setup development, compared to the choices made at other facilities, mainly crystal heat-load and radiation-damage issues. However, high-repetition rate is expected to allow for unprecedented output characteristics. A two-chicane HXRSS setup is found to be optimal for the European XFEL. In this paper we discuss the physical choices peculiar to that facility and simulations done, which allow us to fix the parameter for the setup design.