I know this can be done through the Akashic records. Apart from that, my working theory is since we are living in a matrix that thrives on connections and synchronicity, the information can be accessed by one who is open or trained to perceive it.
So basically all timelines are connected to the individual psyche in some way.
This is really just a stab in the dark tho…
You. People can see your past/present when you associate those circumstances as yours, as a part of your identity. Once you detach and dissociate, all people will ever see is their projections, because you have nothing tied to you.
To see your past and learn from it, and succeed? A ritual for knowledge, asking for truthful and complete knowledge. If it is accepted the deity that will respond will go through your life and tell you of past mistakes that were critical to blocking your success and other mistakes, opportunities you should taken advantage of to succeed.
maybe telepathy? I’ve heard our own spirit/higher self saves all experiences and memories, so even the things you forgot completely could be read by a experienced telepath, it’s an interesting theory. let’s assume that telepaths can not only read thoughts but they can also see, hear and taste our memories, it would be possible to see a person’s past