For CR to know which record is oldest, it has to return all of them. It can't truly 'select' the oldest.
To display the oldest you can do it two ways:
1.
A. Group by Product and again by Vendor
B. Sort by date in ascending order.
C. Hide the details and put the fields on the vendor's Group Header, which will display the oldest.
2.
A. Group by Product and again by Vendor
B. Create a Minimum summary of the date
C. Add a Group Selection formula that says:
Maximum ({Date},{Vendor}) = {Date}
Ken Hamady
On-site custom Crystal Reports Training and Consulting.
Quick Reference Guide to using Crystal in VB.