app/layout.js export const metadata = {
  title: 'Acme',
  openGraph: {
    title: 'Acme',
    description: 'Acme is a...',
  },
}
app/blog/page.js export const metadata = {
  title: 'Blog',
  openGraph: {
    title: 'Blog',
  },
}
 
// Output:
// <title>Blog</title>
// <meta property="og:title" content="Blog" />
In the example above:
title from app/layout.js is replaced by title in app/blog/page.js.
All openGraph fields from app/layout.js are replaced in app/blog/page.js because app/blog/page.js sets openGraph metadata. Note the absence of openGraph.description.
If you'd like to share some nested fields between segments while overwriting others, you can pull them out into a separate variable: