Is there a way to "rotate" the direction of addForce (without using addRelativeForce)?

Trying to word this best I can. say I add this to a rigidbody object:

 Vector3 dir = new Vector3(1, 0, 1);
 rigidBody.addForce(dir);

From a top-down perspective, this will push the object up-right (in respect to the world’s coordinates), but I want it to move up-left, and instead of doing: dir = new Vector3(-1, 0, 1), is there something I can do to dir or addForce to move the object up-left while keeping dir = 1, 0, 1?

kind of like “rotating the whole world” instead