How can I declare a symlink in configuration.nix?

I know how to do it in home-manager;)

home.file = {
  ".netrc".source = /home/b0ef/ds/platform/conf/;

I need to make a symlink to a file in /etc, so I can’t use home-manager

In similar way with environment.etc.<name>.source<name>.source&from=0&size=50&sort=relevance&type=packages&query=environment.etc

right, but how can I make it a general directory or subdirectory under etc?

, like