In the ART application, it is possible to choose: "Version history" from the context menu that will open the 'Version History' application. 
It is important to refresh this list to include the most recent data. (using the 'Refresh list' icon)

Entering any of the item lines showing the previous, and current, versions will open a 'Changes in Version' popup where all the changes for the version in question are listed. 

The criteria for a version to be listed here is that the user has written a 'change note' for the version.
If you want to have a change note on a part in the KIT, you need to make a revision (change) of the part.

For sub kits this information is added to the 'ChangeNote' area at the bottom when defining a new version of the product:

For products with class:P, it is the information added in the 'ChangeNote' box:


'Changes in version'

When on the main kit, the change notes will be visible for parts & sub kits where a change note has been added.