Explanation
Cherry-pick a pull request
To copy changes made in a pull request to another branch in your repo, follow these steps:
In a completed pull request, select Cherry-pick, or for an active pull request, select Cherry-pick from the
... menu. Cherry-picking a pull request in this way creates a new branch with the copied changes. Merge into a target branch in a second pull request.
In Target branch, enter the branch you want to merge the copied changes.
In Topic branch name, enter a new branch to contain the copied changes, then select Cherry-pick.
Select Create pull request to merge the topic branch into the target branch to complete the cherry-pick.
Reference:
https://docs.microsoft.com/en-us/azure/devops/repos/git/pull-requests