All Inboxes Disappeared

In Mail, I have lost the option to select “All Inboxes” from the Mailbox List on my MacBook Pro. It disappeared and is no longer a choice.  Is there a way to get “All Inboxes” back?  My 2 emails accounts are separate now. I have to select each account separately in oder to read all emails. (My iCloud email inbox and ISP provider inbox are separate.) I have all my emails in each separate inbox so that is not an issue.

I am running Big Sur, Version 11.1 on my MacBook Pro. My iPhone and iPad don’t have this issue.

Note: When I select Message/Move to or Copy to I see All Inboxes as an option. I still can not figure out how to get All Inboxes back on my Mailbox List though.