SOURCE

const arr1 = [1,2,3,4,5]
const needRepeat = (node)=>{
    console.log("node:",node)
    if(arr1.find(item =>item === node)){
        return true
    }else {
        return false
    }
}
const arr2 = [4,5,6].filter(needRepeat)

console.log(arr2)