The "Buy Box + Shipping" column displays the Buy Box price received from the SQS reports via SP-API. A green check mark  appears when your price matches the Buy Box price.

Click the "Listing Health > Listings match Buy Box Price" to view listings that have the same price as the Buy Box offer.

The listings shown under this filter are not necessarily in the Buy Box, but they have a good chance of being included in the Buy Box rotation.