Using Shape Builder Tool, How can we keep orignal shape as it is and editable.

In Illustrator there are different ways to get these kinds of live pathfinder constructions.

Apart from Live Paint you may use live compound shapes in the Pathfinder palette. Or you may use live Pathfinder effects (see Effect menu) which are usually applied to groups, layers or some other container objects.

And then there is the Shaper tool (not the Shape Builder tool) that can do it as well. That's the tool that is used in the video you posted. It creates so-called Shaper groups.