Netlify homepage w/ Ghost in subdirectory

Yes you can! Nginx is a reverse proxy, so you can configure one location block to try netlify and one to try your ghost instance! Here’s a snippet from what I use:

location / {
  try_files $uri $uri/ @netlify;
 }

location /blog {
  # Include Ghost config here!
}

location @netlify {
  proxy_pass https://<SITENAME>.netlify.com;
  include /etc/nginx/proxy_params;
}