The best way to host your internal job board on your intranet is to use the Harvest API: https://developers.greenhouse.io/harvest.html#get-list-job-posts and to programmatically construct the links to your internal job board.
You can find more information on how to host your internal job board externally here:
Can I host my internal job board outside of Greenhouse?
Applies-To: [users with API permissions]
Keywords: [internal job board, host, intranet, internal jobs]