Displaying Change Logs 
You can track which field values in comparison objects and comparison instances were changed, or deleted by whom and when.
The following fields are tracked:
Header data attributes
Multi-lingual descriptions
Source-specific parameters
Variable filter criteria (comparison groups only)
Note
Inserted field values are not displayed in the change log. The system only displays updates (old and new field value) and deleted values.
Choose a comparison object or a comparison instance.
Choose Display Change Log.
The system displays all change documents for the object or instance.