The physical drive has absolutely no relevance with SMB.
If you right click on a folder and share it, the folder itself appears at the root of the SMB path.
Create a folder called scan on the c:\ drive, the actual path is c:\scan, now share it (path will be smb:\\PC-IP\scan)
Now put a folder called scan2 on d:\ and share it. (path will be smb:\\PC-IP\scan2)
Now hold down your Windows key and tap the letter R
Now in the Run prompt type \\192.168.1.12 (replace the IP with your own IP address for the PC)
You will get a new File explorer window opened that shows anything shared on the PC, like so:
Drive letters do not exist in SMB, nor do they matter, only the share does.