In this example you will see how to edit the shared edge in the Map Topology to simultaneously update several watershed features in two different feature classes. The light blue guide lines in the background image show where the feature boundaries should be.

Double-clicking the edge switches the Edit Task to Modify Edge and lets you see the vertices of the topology edge, that are shared by several features. You can move the individual vertices with the Topology Edit Tool and all of the features that share the edge will be updated.