Yes,it is theoretically possible but not in a practical way. According to GR, space and time are not two mutually independent dimensions but connected through space-time fabric.When an object of masses are there,it create space time curvature on that fabric. Since black hole have very high density ,so it creates an enormous amount of curvature.
Now, think space time fabric as a thin piece of paper,where by folding it in a way that two distant points are closed by a tiny tunnel (as here the width of the paper). This is possible also in a real case of space time geometry.And that tiny tunnel are shortcuts through space-time between two locations of the universe.
That tunnel(also known as worm hole) connects two different locations where one side is a black hole and opposite site there is a white hole.
Though this idea is highly speculative and it is believed that wormholes are highly unstable. It would be saying too much speculation that we could do time travel by that wormhole.
The deepest problem is that we have zero observational evidence that wormholes exist at all. They are valid solutions to Einstein's field equations, but mathematical possibility doesn't guarantee physical reality.