you can use "Versioning (or Team in v4)>Design Version History" in order to see all changes committed into repository. You can see changes (at object level) between revisions or compare (merge) to local version.
Otherwise you need to checkout versions of design at revisions you want to compare and can use "Tools>Compare/merge models" or "File>import>Data Modeler Design" in order to see all changes.
Thanks for your input Philip!
I was able to checkout the previous version and able to compare with the latest model to see all changes.