Custom field values can be exported in Excel (XLSX) format ready to open in your favorite spreadsheet program. This is done by clicking the Export button above the selected scope's field definitions:
Once the export is complete, the file can then be modified and imported into the same store for doing bulk updates or imported into another store for migration data
An export of custom field values contains only values for the custom fields, not the field definitions themselves. These need to be set up beforehand in the store you are importing to, either by copying & pasting them or by linking your stores and performing a synchronization of the definitions
What's in the file?
The first row in the Excel file is a required header line with columns A and B "_id" and "_info" followed by one or more custom field names (including their namespaces).
The actual values for an _id column on rows 2 and onward depend on the exported object type and the options chosen when setting up the export. These are the defaults:
Handles are used for products, collections, pages, blogs, articles
SKUs are used for variants
Email addresses for customers
Order numbers for orders.
The _info column contains information associated with the _id - like the product title or the customer's name. This is for information only and changing this value won't have any effect on any later import.
Third column (C) and onward contain the custom field values associated with the object instance.
Exporting subsets of data
ACF also allows for export of a subset of either products', customers' or orders' custom field values from within the Shopify admin. From the relevant object list (such as product list, customer list, etc.), perform a Search or Filter and then bulk select the objects for which you'd like to export the custom field values. Then select the "Actions" menu and click "Export Custom Fields".
Export of subsets is currently limited by Shopify for selections of 50 objects or less
Exports run in the background. While an export job is active, the icon next to "Export values" will change to a spinning "gear" icon. Due to Shopify limits, you are encouraged not to start any additional exports until the current job has finished.