How to restore a single file deleted 6 months ago - using M365 Backup?

My friend's company uses Sharepoint Online, but relevant folders are synced to their OneDrive so they manage everything in File Explorer. I have Microsoft 365 Backup enabled on their Sharepoint site. This company has all the parent folders in "Site Contents". These folders include Sales, HR, Clients, etc. I need to restore a single file out of Sales but it appears I need to restore the entire site first, sync the Sales folder from the site ending in /R0 to my OneDrive, then copy/paste from my File Explorer. Yes, I am a NOOB in Sharepoint. What's the right way to grab this file? And if it's ditching M365 Backup, then that's what I'll do, but I still need to get this file.