A "repeater" field allows administrators to add more than one instance of the same field and rearrange the values.
For example, you may have a field called "Inputs" that varies. On "product A" it may have 2 values and on "product B" it may have 5 values. In that case, a repeater field is ideal.
Custom Fields is the only metafield app in the Shopify App Store with this functionality.
Create a new Field Collection field. Field Collections are under the Groups field types.
Add the field to the Field Collection that you want to act as a repeater
Content Entry Form
When editing content, your administrators will see the field in this format.
Default Liquid Code
The Edit Code section will automatically generate a snippet that loops over the values the user enters. You may customize the output if you wish.