Using the various zoom-related icons on the Dependency Viewer toolbar you can zoom in and out of any dependency map.

If your mouse has a scroll wheel, you can also use that to zoom in and out of dependency maps. If you click the scroll wheel button, the mouse arrow becomes a hand that grabs the dependency map, at which point you can move the mouse in any direction to drag the dependency map as needed. Click the scroll wheel button again to release the map.

Clicking the Overview Window icon on the toolbar opens a small window (called the Overview Window) in the lower right corner of the Dependency Viewer tab, which displays a scaled down version of the current dependency map. The Overview Window is primarily used for panning, and is useful when you are already zoomed in deep into the current dependency map. To pan using the Overview Window, click somewhere inside the Overview Window, then drag and release the map as needed. When you release, the larger dependency map is also panned.