Group Products Instructions
To Group Products:
1. Create a collection with title is the product title you want to display.
2. Collection description will be the "Grouped Product's fake option name". In the demos, I used "Colour" and "Length".
https://down-to-science.myshopify.com/admin/collections/60536193079 (Colour)
https://down-to-science.myshopify.com/admin/collections/60550283319 (Length)
3. Products in this collection will be grouped together. You can create an auto collection with condition(s) or manual collection and add products to it.
In the demos, I simply created auto collections with condition: Product title contains ...