To search for recently archived emails in Gmail, open Gmail and in the search box, type “in:archive” (without the quotes) and press enter. It will show only messages that have been archived (not including messages in the inbox like All Mail).

The magic of this command is that now the dates of the messages represent the date of archival (not the date of receipt)! The results should already be sorted by date that the message was archived, and when you scroll down to the moment of your accidental archival, you should see a whole bunch of consecutive messages. These are the ones you accidentally archived.

From: https://medium.com/@MattGyverLee/oops-i-just-archived-a-bunch-of-gmail-messages-71aae70322d7

Searching in:archive sorts by archival date.

Medium article about recovering archived emails:

To search for recently archived emails in Gmail, open Gmail and in the search box, type “in:archive” (without the quotes) and press enter. It will show only messages that have been archived (not including messages in the inbox like All Mail).

The magic of this command is that now the dates of the messages represent the date of archival (not the date of receipt)! The results should already be sorted by date that the message was archived.