FEMAP requires that you split a solid down in to "sweepable" regions for hex meshing. For your part, I divided it down into 16 solids. I used mosly - Geometry - Solid - Embed Face.
When you "size" the geometry for hex meshing, FEMAP will automatically determine the sweeps, and the connected faces to make sure all the nodes are merged, here's the resulting mesh -
I have attached the split-down Parasolid file.