Both Fujifilm GFX 50S and Hasselblad X1D have 51.0 MP resolution sensors but Fujifilm GFX 50S's sensor is Medium format (44 x 33 mm ) and Hasselblad X1D's sensor is Medium format (44 x 33 mm ).
Since Hasselblad X1D's has a larger sensor area with the same resolution, this means that it also has a larger pixel area hence better light collecting capacity for a given aperture compared to Fujifilm GFX 50S.
Below you can see the GFX 50S and X1D sensor size comparison.
Fujifilm GFX 50S and Hasselblad X1D have sensor sizes so they will provide same level of control over the depth of field when used with same focal length and aperture.