[masoric]

You can nest projects in all versions of OmniFocus. In your project, create a task which will be a nested project. Then create a 2nd task (which will be the first task in your nested project.

Tap the 2nd task to bring up the action dialog box. At the bottom of the "info" tab ther is a button titled "Move". Tap this button and choose the first task. This will nest the 2nd task inside of the first.

In Omnifocus nested projects are actually called "action groups".