Baffles for gyroid lattice

Hello,

Does anyone know how to create automatically baffles to close gyroid lattice structure on inlet and outlet? In the video (https://www.ptc.com/en/resources/cad/webcast/revolutionary-heat-exchanger-with-additive-manufacturing/thank-you) Andreas Vlahinos says that it is possible to create inlet face exposed on only one fluid domain with variable gyroid thickness. I have done some tries but I am able to cutoff both or none.

Any tips?