Restore mailboxes under "ALL INBOXES" that were accidentally deleted

New to using Apple Mail - have been a Spark user for years, but decided to give Mail another chance now that Big Sur is here.

I thought I was removing my combined DRAFTs, ARCHIVE, and SENT mailboxes from my favorites, and I suppose I deleted them instead, since I cannot find these mail boxes now. Is there a way to restore them? I still have the SENT, ARCHIVE, DRAFTS under the separate accounts, but would really like to be able to access these in a combined folder.

Thanks.