How can I create the diff using git, such that I see the hunks in the diff
file in Berkeley context format, and see only the changes I did ?

Please try to propose me scripts of creating tabs that keep frames. It is
not too clear for me how such scripts can be created , such that you find
the tabs of type frame useful for you. If you propose me such scripts as you
need it, I can modify the code to make it behave on your needs.

Alin