Right click on the 3D surface and you'll get the functions.
You can use "Extrude" or "Extrude along path"...

Ok...
So, if the 3D surfaces are in the X/Y plan, you can use "Wireframe".
Then, convert the 2D lines to 3D lines with "Convert elements" (and click "Yes" to get polygons).

There is a tool in 3D Modeling module called Extract 3D Curve. It will extract all edges of 3D solids or 3D surfaces. Beside 3D lines you can also select ISO curves.

Select an object you wish to convert. After that you can select every edge you want or use Bracket to select all edges at once.
Allplan will place extracted curves in their original position. You need to delete 3D solid / 3D surface to see extracted curves.