The History tab from the Team Development dialog enables you to inspect all the commits done; get the objects list and compare differences between your local object and the one on the server side.
The operations shown in the context menu depend on whether or not you are looking at the commits in the same version you are connected to (ie: which version of those in your GXserver is selected on area 1).
If you are looking at the commits in the same version your KB is connected to, then you can perform a Revert a Commit on any of them.
When you are looking at the commits that were done in other versions, you can instead Bring Changes from them.
On the details of a commit, for any object you have two options available:
The Show Differences command will open a comparator window detailing the state of the object Before and after the Commit.
The Show Server History operation will display a new screen where you can check the detail of all the commits in which the object was involved.
The Show Log option changed to Show Server History since GeneXus X Evolution 2 Upgrade #2.