How do I find an older profile in a Time Machine backup to an external HD with Catalina

[Garat]

I had to have my iMac reset to original software by Apple and so lost everything on it and it is now back to factory settings. I am trying to add back Thunderbird. I have a time Machine back-up on an external hard drive. I need to find a previous profile (the last profile before resetting the iMac) on the TM Back-up and replace the new d/l of Thunderbird profile so I can get all of my previously saved emails. I have tried everything I could so far but I can not find the Thunderbird profiles on the backup.