Can I split multiple values stored in one Shopify metafield into separate report columns?

Yes. Shopify can use a text or list metafield in reports, but it has no option to break one stored value into separate numbered columns. Report Pundit reads the stored value and places each item in its own column (Skin Concern 1, Skin Concern 2) beside your sales data.

Why the values look like ["A","B"]
List metafields store several values inside a single metafield, and the stored value is a JSON array. That's where the square brackets and quotation marks come from. Shopify reports can group and filter by supported metafields on products, variants, customers, and orders, including lists of single line text. To be available, the definition needs Filter or group data in Analytics turned on. What Shopify doesn't do is spread one stored value across numbered columns. Natively, that means exporting to a spreadsheet and splitting the text by hand every time the report is pulled.

How the split report works in Report Pundit
Take a skincare store that records a Skin Concern metafield on each product. The report is built on a sales report, with the original metafield kept as a reference column and the split values beside it:

• A moisturizer stored as ["Dry Skin","Sensitive Skin"] fills Skin Concern 1 and 2.
• A serum stored as ["Anti-Aging","Dark Spots","Dullness"] fills the first three.
• A cleanser stored as ["Oily Skin"] fills only the first.

Other sales fields and product details can sit in the same report, and the data follows the selected date range.

A value lands in a numbered column based on the order it was saved. "Sensitive Skin" can sit in column 1 on one product and column 2 on another. To total sales for one concern, filter across all the split columns rather than reading a single one.

This is a custom build. The fastest route is sending the metafield name and a few sample values to the Report Pundit support team. For adding a metafield as a report column, see How to Use Custom Properties. For wider metafield reporting, see Shopify Metafields Reports that work like magic for business. For how updated metafield values carry into reports, see Do updated Shopify metafield values automatically show up in scheduled reports?