When checking settings of custom labels in Google Inbox, one can see the filters that are used to put emails there. However, such setting is not available for the special labels e.g. Purchases, Finance, Updates, etc.
Now, I do realize that there is a classifier underneath (unlike custom labels), but when an email is moved to the label, you are still being asked if all emails from this address should be moved there. It would be good to see which addresses were marked this way. Is it possible?