In the Collaborator Enterprise Client GUI, click “Add Subversion Diffs”. Click the “Revisions” tab. Change the Subversion URL to be the top level of the directory structure you want to diff. The “Before Revision” should be the last SVN commit that was reviewed (see SVN’s “Show Log” for the revision ID).
However, at this point, you cannot chose to include/exclude some files from some of the revisions. This is useful when certain things should be submitted to the repository but not reviewed (*.bin files for instance). This would be a nice feature.