Display virtual adapters in network settings
Solution 1:
Finally, I found the answer in the Parallels knowledge base (https://kb.parallels.com/125286):
Issue
After upgrading macOS to Big Sur, Connect Mac to this network and Show in System Preferences options disappeared from Parallels Desktop preferences > Network..Show in System Preferences option can not be selected so Host-Only network cannot be found from macOS System Preferences > Network.
Cause
These features are now hidden due to macOS Big Sur restrictions (KEXT-less network mode): In macOS Big Sur Apple restricted usage of kernel extensions and Parallels Desktop does not load them by default, instead it uses macOS own built-in mechanism.Workaround
Downgrade to Parallels Desktop 16.0.1 or earlier - make sure the version is compatible with macOS Big Sur.