Assuming your JIRA is connected to some kind of source code management (Bitbucket or Github). The branch / commit name must contain the JIRA issue key.
Jira: assign an existing git branch to an issue
Creating the branch though the UI is just a convenience. The important thing is that the name contains the JIRA key. If only one developer is working on the branch, it's fairly easy to just rename (delete + add) a branch with the appropriate name.
To find all branches / commits related to an issue, there's the Development Panel on the sidebar right.