The features described in this section are only available in the OmniGraffle Professional version. If you do not have the professional version, you can skip this section.
If you've ever created a really big OmniGraffle diagram with hundreds of shapes, you'll soon find that zooming in and out, and moving around your diagram all the time, is on the brink of annoying.
If your diagram is built in a way that makes it possible to group certain parts of your diagram together—you can create a subgraph.
A subgraph is a special kind of group for shapes that can be collapsed and expanded on command. Shapes within the subgraph are hidden and shown accordingly. Any lines to shapes within the subgraph will become lines to the subgraph when collapsed.
To make a subgraph is as simple as selecting a few shapes, then using the Arrange | Group as Subgraph menu command. Your shapes will now be enclosed in a rectangle which can be styled as you want.
To ungroup a subgraph, use the Arrange | Ungroup menu...