app/dashboard/layout.tsx export default function DashboardLayout({
  children, // will be a page or nested layout
}: {
  children: React.ReactNode
}) {
  return (
    <section>
      {/* Include shared UI here e.g. a header or sidebar */}
      <nav></nav>
 
      {children}
    </section>
  )
}
Good to know:
The top-most layout is called the Root Layout. This required layout is shared across all pages in an application. Root layouts must contain html and body tags.
Any route segment can optionally define its own Layout. These layouts will be shared across all pages in that segment.
Layouts in a route are nested by default. Each parent layout wraps child layouts below it using the React children prop.
You can use Route Groups to opt specific route segments in and out of shared layouts.