In DraftSight Enterprise or Enterprise Plus, there is a useful add-in called Drawing Compare.
Drawing Compare can be used to instantly identify the differences between two very similar drawings, e.g. the same drawing with different revision.
Step 1: Click at Draw Compare
Step 2: Browse to Add Drawing1, and then Drawing 2
Step 3: Click at Compare Drawings
Step 4: Easily Identify the Difference between both Drawings