SoftPerfect Network Scanner can detect any shared folders that are accessible via the SMB protocol, which is usually the case for NAS devices.
If it does not detect them for you, it may be due to
guest access in SMB2 and SMB3 being disabled by Windows security settings.
To work around this, you can set the Network Scanner to use its own implementation of SMB, which is not subject to those restrictions. For that, open NetScanner
Options, go to the
Shares tab, and switch the method to
SMB2 Library.