Above is the example I'll be using. This is a multi-page document that shows a simple web site layout. As you can see there are also several layers I used to organize the work and find things easier.

What I want to do is to remove all of the background and navigation elements on the bottom page so I can work on a different design. This may seem easy without this tip, but there are lots of objects to select on that layer to remove. So this tip will make things much easier.

First make sure you are set on the page you want to be working from. In this example, I want to make sure I'm on page 2 so I look at the bottom of my document to set the page.

Next I go to the Layers panel and Option (Alt) + Click on the layer name that contains the objects I want to be working with. This selects all of the objects on that layer, on all of the pages like shown above.

Now we are going to use a command under the Edit menu -> Select -> Invert Selection. This command does not have a keyboard command as default, but it's a good idea to set one up if you can.

On my Mac, I used Command + Control + A. You can use whatever you like if you can find a combination that isn't take already.

Now go ahead and do the command once. You will notice that it inverses the selection on page 2 but deselected everything on page 1 like shown above. This is good.

Doing the Inverse Selection command one more time gives us exactly what we need. Now as you can see above, all of the objects on that layer are selected and are ready to be deleted. Fast, and very easy.