When you first create a new season, there are no products visible. You can make products from other seasons visible via Set Season Visibility. The prices are season specific, so any changes made to costings will not impact previous seasons
You can select a specific season via the Season dropdown or use Select/Move/Filter to apply further filters
Save is automatic
All Raw Materials required for these products are now automatically visible in this season.
If you now change ANYTHING in the Product Costing except Exchange Rate, Make/First cost or Wholesale/Retail prices - it will carry through to ALL seasons.
For information on how to rename products from previous seasons