I think the video you are thinking about is the Value From a Form video.

If you need to open a different form based on the value chosen, you could set up branching using an  If Then to determine which form to use.

If you could give us a more specific example or mock up of what you want to do we would be better able to help you out.

That wasn't the one I was remembering... although it has good stuff, Thx.

Different form were chosen based on the data not a filtering event. If I remember properly  Richard even was using it to draw connections / artwork in the form ... was it a family tree maybe?
I have a huge connections list of many types of equipment and i want the connection to pull up the correct form to match the next piece of equipment in the circuit. The forms will be different per equipment type but still use the same connections table. All equipment has inputs and outputs, so the basics of the forms are the same but some types of equipment  have additional connection... again from the same table but will need to be a different form. The forms could (should?) cascade... maybe these are subforms...