existsInBothArrays.js

   Here is how you can do it when the items in the arrays are objects.

  The idea is to find the array of only the keys in an inner array using the map function
  Then foreach of those check if they contain a spectific element key in the outer array.

  const existsInBothArrays = array1.filter((element1) =>
    array2.map((element2) => element2._searchKey).includes(element1._searchKey),
  );