Copy changed files to another branch in Git

git checkout <branch> -- path/to/file

By the above command, you can pickup files to copy to another branch.

For example,

1. You've been coding on branch-A for a long time.
2. You wanna open a PR from some files of them.
3. Then, execute:

# Switch back to main
git checkout main 
# Create and switch
git checkout -b branch-B 
# Import subset files to branch-B
git checkout branch-A -- path/to/file