The CNC parts are derived from the original 3D object.
I copied the solid part and converted it to a wireframe object by changing its object type to "Curve".
Then I selected a side view on the copied object, deleting all structures which made it 3-dimensional.
E.g. if you have a top and bottom surface with vertical lines in between, I deleted all vertical lines and the complete bottom surface.
What is left over is a flat 2D "drawing", the top surface in the example above.
If you have a look at the CAD picture of my first post, you see all the 2D parts lying around the solid object.
Then I exported this 2D part as a DXF to be processed further by the CNC software under Windows.
You just have to take care that all curves are closed.
In the CNC software you have to assign such things like outline or inline milling paths and the order in which the different paths are milled.