In other words, if a photon is emitted from source, is it possible to change its course en route either by introducing a gravitational lensing or some sort to change the road it travels (spacetime) before it reaches it's source?
Is this a philosophical or practical question?
You can change the path of a photon in a variety of ways - reflection, refraction, diffraction - it's called optics. Whether it's the same photon is more a philosophy question.
Gravity will change the path of a photon, although you would need a pretty dense and massive object to have any noticable effect. We can just about detect the gravitational lensing effect of Jupiter on the light from a star.
ps. As JohnRennie point out, this is another philosophical point. Yes it is the same photon, but since it is space that curves, from the photons point of view its path didn't change.