https://medium.com/javascript-in-plain-english/how-to-get-the-current-screen-metadata-in-react-within-react-navigation-b9c18206e9c4

getActiveRouteMetadata.ts

/**
 * Crawl through navigation state to get route metadata.
 *
 * @param {*} navigationState
 * @returns {*}
 */
export function getActiveRouteMetadata(navigationState) {
  if (!navigationState) {
    return null;
  }

  const route = navigationState.routes[navigationState.index];

  // Dive into nested navigators as long we haven't reach current screen.
  if (route.routes) {
    return getActiveRouteMetadata(route);
  }

  return route;
}