To undo changes since the last commit, use the Revert button.
Each branch has a list of previous commits and Uncommitted Changes. To show the changes since the last commit, click the arrow to the left of the hamburger menu in the Uncommitted Changes section.
Note:
Reverting a change reverts all changes that have been made since that change as well. Make sure that you understand all the changes that will be reverted before reverting.