In version 5.0.19 and later, you can select Batch_Detail as a table to query on when building a query in Query Entry.  A client can now write a query to check, for instance, if accounts in any batch items have certain Classifications associated with them or not.  In Query Entry, under 'Find Queries' click into 'Query Type' and look for BATCH DETAIL as an option in the pull down menu.  This will enable you search for the desired data.