Follow below steps to display complete the look products.

Step 1:

 From your shopify store admin > Click "Settings" > Metafields and metaobjects > Products

Step 2 : Click on “Add definition” button and add data as below

Name: Complete the look
Namespace and Key: custom.complete_look(Must be same)
Select Content type: Products ( Select “List of products” )

Step 3 : Select List of products and save.

Step 4 : Now go to products from store admin, scroll down to “Metafields” and select products in Complete The Look

Click on Complete The Look field > select products > add product you like to display in page then click on save button.

Step 5: Save product page and it’s done. Check now on product page on front side.