SHELL

git create new branch from existing branch

git checkout -b ＜new-branch＞ ＜existing-branch＞

Create new git branch from existing branch

 Syntax: git branch <new-branch-name> <existing-branch-name>            
 Example: git branch newone master
 Here newone is new branch and master is existing

create a new branch from existing branch in git

git checkout -b subbranch_of_b1 branch1