Hi,
Walking the three is possible using the output’s .grad_fn property to get the first functions, and using the .next_functions property to get higher in the three.
For Functions implemented in python, you can use this python object to access tensors that were saved with save_for_backward by using the saved_tensors or saved_variables properties.
For Functions implemented in C, it depends on the implementation and most of them do not expose these values.