Hi,
do you mean a post-layout simulation? So do you already carried out a parasitic extraction and want to verify functionality after layout?
Please specify the tools you are using for layout, lvs and parasitic extraction. If you are using cadence dfII and assura for parasitic extraction, you get an so called extracted view after parasitic extraction. You can use this view to do the post-layout simulation.
In the attached document these steps are described (in german, but the images carry the important information).
kind regards,
hqqh