If you have multiple versions of one product split into different product listing it may be hard for customers to find the option they want. Using the “Linked products” block you can display additional products as options on your product page.
Enable the product block
Open the theme editor by clicking Customize next to the relevant theme.
Navigate to the product template then click "Add block" within the "Product" section
Move the block and add a label
It's usually best to display the "Linked products" block above the "Buy buttons"
Try adding a label that describes the additional linked products. If the additional products are variants of different color you could update the label to "Color".
Create metafield definition
Navigate to Settings > Custom data > Products
Click Add definition
In the name field type “Linked collection”
Ensure the namespace and key field is
Set the data type as "Collection"
Navigate to the product you’d like to update
Scroll to the bottom and select a collection for the metafield
Metafields can also be updated using the bulk editor