The product is stored in your personal account in 'Analyzed Products' section if you've taken any action on it.

For example: you entered COG, like or dislike an item, add a comment, or save it to Google Sheets. All these actions could be taken either in extension on Amazon product page, or in Quick View, or in Side panel view of Seller Assistant.

In supplier column you will see the current Buy Box seller (the one who was holding Buy Box at the time of analysis).