You can create different report styles that use different crystal reports allowing you to organize the data differently. Additional tables can be linked into a copy of the RDD, for example if there is a field with a part number in it and the Part table isn't already linked in you can link the Part table. This will bring in the part related data for that part.
You can't control the record selection beyond what the original report screen allows though. You can add filtering to your Crystal report that can reduce the data-set once it gets to Crystal.
To go beyond this you would need to build a BAQ or other query to build your data-set.
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