In AutoCAD, you can cut a 3D solid to produce new 3D bodies in several ways. Consider two ways.
The easiest, use the CUT command (_slice in English version). At the command prompt, type CUT, press Enter, select 3D solid, and then the command prompts you for several options for cutting the solid. You can cut a body by specifying three points (the default) by selecting a flat object, a surface, or one of the coordinate planes (XY, YZ, ZX).
Another way to create another 3D solid completely intersecting the one you want to cut. Next, using the command SUBTRACT (_subtract) cut the desired 3D body by subtracting from it another 3D body.
However, after you use the command REDTEL (_separate), to actually divide the body into several.