Yes, Sketchup has long had this capability of exporting 2D arcs and circles in .dxf. There are two pathways being discussed in this thread, one is the native function that leverages the stored metadata for arcs and circles using the export 3D function and paralel projection, that method is outlined here:
The second is a newer development using the very good extension OpenCutList which uses a different method of recognizing and building DXF and DWG arcs and curves by recognizing collections of edges and converting them. The advantage of this is that the curves need not be circles or strict arcs in Sketchup. I use this extension too and find it works well as long as there are enough segments to your arc to be recognized.
Which method you use I think depends greatly on the complexity and frequency of the files you need to output. I have used the first method for years, but use a combination of both.