Сравните вложенный массив с другим массивом

var movieList = [
  {
    title: "The Dark Knight",
    genre: "Action"
  },
  {
    title: "The Godfather",
    genre: "Crime"
  },
  {
    title: "The Shawshank Redemption",
    genre: "Drama"
  },
  {
    title: "The Shawshank Redemption 2",
    genre: "Drama"
  },
];

let result = movieList.reduce((acc, current) => {
  const genre = current.genre.toLowerCase();
  (acc[genre] = acc[genre] || []).push({
    title: current.title
  });
  return acc;
}, {});

console.info(result);

const movietList = [
    {
        title: "The Dark Knight",
        genre: "Action"
    },
    {
        title: "The Godfather",
        genre: "Crime"
    },
    {
        title: "The Shawshank Redemption",
        genre: "Drama"
    },
];

const genres = ["Action", "Crime", "Drama"];


const groupBy = (movietList.reduce((acc, {title, genre}) => {
    if (!genres.includes(genre)) {
        acc[genre] = []
    }
    else {
        acc[genre.toLowerCase()] = {title}
    }
    return acc;
}, {}));


console.info(Object.entries(groupBy).flat());