With the attribute DOMTESSFACTOR you can scale the fineness which is used for tesselating trim curves of nurbs surfaces by a factor n.
Let f be the current fineness with which nurbs surfaces are tesselated (given as the ratio of the absolute tesselation tolerance to the diameter of the bounding box of the control points of the surface (for example 0.01 would mean that the tesselation tolerance is 1 percent of that diameter)
On default the same ratio is multiplied with the diameter of the parametric domain of the surface to get the absolute tolerance which is used for tesselating trim curves.
But since the trim curves are visible as boundaries of the surface, one often wants to tesselate them finer as the surface itself. When you for example set a DOMTESFACTOR of 0.1, then trim curves are tesselated 10 times finer then the nurbs surfaces themself.
n must be a number node.