Mission Control to App Exposé

If you activate Mission Control whilst hovering the mouse over an app in the dock, it will do an Exposé for that app.

Activating Mission Control any other time will do a global Exposé as you say.

While in mission control, if you slide one finger up on the magic mouse (imagine it's a 2 two finger swipe with a trackpad) whilst hovering over the app windows, it'll Exposé the selected app's windows

In one of the earlier developer previews you could slide one finger up (on the magic mouse) over a dock icon while in Mission Control and it would trigger a per-app Exposé. Alas, it seems this feature has been removed.

There could be a hidden switch to turn it back on, but I've not had a play around with those 'secrets' apps to have a look yet.

• Swipe up with 3 fingers = show mission control.
• When mission control is shown, move your mouse to the app window, and
• Swipe up with 2 fingers

This will show the app's windows.