Earlier quoted context omitted.
It's not a philosophical notion.
The book "Physics" was written by Aristotle, who is so much of a philosopher that he's often called "The Philosopher". He's also the author of a book called "Metaphysics", pretty much the quintessential field of philosophy. The entire point of this conversation was that some fields, including physics, get split off from philosophy, leaving behind a mishmash. But many scientific fields absolutely began as aspects of p…
They didn't quite know how to name the last book since its contents were so abstract and unrelated to the everyday world, so they simply called it "the book that comes after the Physics," which eventually became known as the Metaphysics. It is worth noting that the title is a specific reference to the book, not to any notion of the subject matter somehow transcending physics. After all, why physics, in particular?
In the light of that, it is even more jarring to see the term 'metaphysics' being used to describe spiritualism and new age mysticism.