For this one we need a “Rhombic dodecahedron” which is none of our Primitives, so have to do it on our own.
We start with a Primitive “Octahedron”
Select in the Remeshing Menu, 3-Conversion, Vertex Truncation
Set the Offset to 0.5
Now we got a “Cuboctahedron”
The Dual of a “Cuboctahedron” will give us a “Rhombic dodecahedron” . Go again to the Remeshing Menu and select Dual
Now we got the “Rhombic dodecahedron” but it’s kind of starnge. Go to the Tools Menu and select Planarize All Faces under Objects.
Finally we got the “Rhombic dodecahedron” . You might save it.
Now select the “Add Handle” Tool and join the faces as you wish.
You might get something like this.
Apply a Doo Sabin Remeshing
There’s one possible configuration with the Add Handle Tool to create one Face loop around the hole shape. Now open the Ring Modeling Thickness Tool, select your Loops and press Create Crust
One more Doo Sabin and that’s it. If you do everything right it should be one connected object. Just select one Face and press “=“severall times to grow the selection.