ArcGIS derives CAD symbology from the graphic properties stored in the CAD file. By default, CAD data is displayed as the author originally intended. You can change the symbology and save it with your map document. Changing CAD symbology does not alter the CAD file nor does it change symbology in other map documents referencing the same CAD data.
In addition to symbology, you can also drill down into a CAD feature layer and control the visibility of the drawing layers defined by the CAD file. This enables you to display specific CAD geometry in ArcMap that may otherwise be difficult to isolate and work with.
And lastly, if you need a more precise method to filter out unwanted CAD geometry, you can run definition queries against the attribute values in the CAD feature class virtual table.