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.