git change the parent branch

Question

The short story is : I have created Branch A out from the Develop Branch then I created Branch B From Branch A

Answer 1

You are looking for git rebase --onto, since what you want to do is basically rebase only the commits from branch B onto develop.

There is a very good description of rebasing in the official git documentation. See section More Interesting Rebases for an example like yours.

Your example would be solved by git rebase --onto develop branchA branchB.

Also see the git rebase documentation.