Not much to do, here. There has to be exactly one floor/visualization source surface in the model per thermal zone you want displayed. If not, create them. If you have previously used the model for daylight simulations with DIVA, there’s probably already one reusable node source surface drawn per space.
Keep in mind that the node surfaces need to be valid, especially because the Mr.Comfy daylight component uses zone volumes extruded from the selected surfaces to find daylight sensor points included in them- so if you mess it up, something will go wrong.
Hint: if you use a surface component to reference polysurfaces, only part of the whole surface will be selected. Use the BREP component or generate whole surfaces prior to selection.
Daylight mapping from Daysim *.ill and *.pts files (as of Mr.Comfy 0.21) requires no geometry to be present in the Rhino scene at all- so if all you want to do is visualize daylight data, you can do so without any geometry present.