The closest thing to that that I'm aware of is barnacl.es<p>That site is aimed at entrepreneurs, with a particular focus on people who are bootstrapping instead of pursuing VC money. A lot of the discussion there tends to involve marketing, although the site isn't necessarily aimed at marketers per-se.
There is a really great Slack team for SEO & Marketing called Online Geniuses (<a href="https://onlinegeniuses.com/" rel="nofollow">https://onlinegeniuses.com/</a>). It's not really "HN like" but it's a really great community.