demo.ts

import DocumentNested, { DocumentNested } from './DocumentNested';

interface Document extends DocumentNested {
  name: string,
}

interface ParentComponentProps {
  document: Document,
}

function ParentComponent(props: ParentComponentProps) {
  return (
    <>
      <h1>{props.document.name}</h1>
      <DocumentNested document={props.document} />
    </>
  );
}