Official ReactJs documentation recommends to create components following the dot notation like the React-bootstrap library:

<Card>
  <Card.Body>
    <Card.Title>Card Title</Card.Title>
    <Card.Text>
      Some quick example text to build on the card title and make up the bulk of
      the card's content.
    </Card.Text>
  </Card.Body>
</Card>

It is very easy to create this structure with the help of a class component:

const CardBody = ({ children }) => <div className='body'>{children}</div>;

class Card extends Component {
  static Body = CardBody;

  render() {
    return (
      <div className='card'>{this.props.children}</div>
    );
  }
}

But it's also recommended to use as much as possible functional component. Unfortunately I don't know how to achieve this using only functional component.

If I follow this way, I'm no more able to use Card as a component because he is now an object of components:

const Card = {
  Component: CardComponent,
  Body: CardBody
}

export default Card

I'd have to use it that way, and it's not really what I want:

<Card.Component>
  <Card.Body>
  ...

Do you have any idea how to do that?

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>
);

For functional components

const CardBody = ({ children }) => <div className='body'>{children}</div>;

const Card = (props) => (
  <div className='card'>{props.children}</div>
);
Card.Body = CardBody

And then use it like

<Card>
  <Card.Body>
   ....