It's certainly true that many General Counsel positions aren't openly advertised. When I recruited my successor to my most recent GC role I tapped into my network and found a highly suitable person to replace me. To increase diversity at senior in-house level, it would be helpful if recruitment were open. Maybe a website specifically to advertise GC positions?
Until something like that happens, the advice in this article is definitely worth following if you're hunting for such a role.
General counsel, head of legal and regional counsel roles are undoubtedly rare in the legal recruitment sector. A scarcity of roles combined with a highly networked process when it comes to recruitment at this level make for an often discreet hiring process, in stark contrast to senior hiring within private practice. The roles are almost certainly out there, but the trick to accessing them can lie in correct personal marketing. C-suite positions are almost always filled via executive search firms, by word of mouth or, increasingly, via social media. To tap into this, senior counsel need to be active networkers with a minor degree in social media profiling. On a practical level, this means getting yourself out there, publishing, highlighting your successes on social media sites, joining LinkedIn groups, attending functions, seeking out opportunities to speak at industry events