In function component you can do like so:
// Card.react.js
const Card = ({ children }) => <>{children}</>;
const Body = () => <>Body</>;
Card.Body = Body;
export default Card;
// Usage
import Card from "./Card.react.js";
const App = () => (
<Card>
<Card.Body />
</Card>
);
Or, you can exploit named exports:
// Card.react.js
export const Wrapper = ({ children }) => <>{children}</>;
export const Body = () => <>Body</>;
// Usage
import * as Card from "./Card.react.js";
const App = () => (
<Card.Wrapper>
<Card.Body />
</Card.Wrapper>
);