Backup without mount

Hello!

I'm trying to fix my broken NAS and I've gotten to this point:

- the hdd is hooked up in my pc, which boots up thrugh usb
- the disk shows up with fdisk -l
- I am unable to mount the disk due to a bad superblock.

Fixing the superblock isn't my main priority atm, my first objective is to retrieve essential data. I have 32 gb of storage on a second flashdrive, not enough for a full image (which would consume around 1,5tb).

My question: is there any way to navigate to key folders, backup their contents, without actually mounting?

Thanks!