In order to get history of a locator, click on the key of that locator and then click on History.
This will show all of the versions of the selected locator in a popup presented below.
In order to see the delta between the selected version and the current version, just click on the revision date for that version. Once clicked, the following page appears and the delta between that version and the current version is highlighted in yellow as follows with the current version shown on the left. You can individually select each modification and hit apply to revert a specific change back to an older version.
