Move object on Z Axis


I am trying to print 1 object with multimaterial, in 2 colors. My faster idea was to cut the object in 2 and select the color of each one, that’s OK. But when I try to move the 2nd object to the top of the first object Slicer always set Z coordenate to 0, not allowing to print one object on the top of another, is that possible with Slicer? Or do I need to design the object with an externat mesh editor?

Is your question related to using 3D Slicer (medical image analysis or visualization application) or Slic3r (3D printing Slicer application)?