可以使用JavaScript的Array.reduce()函数来对两个包含嵌套对象数组的对象数组进行比较，并获取不匹配的对象数组。

比较的思路是：首先比较对象数组的长度，如果长度不相等那么两个对象数组肯定不匹配；如果长度相等，再逐个比较两个对象数组中的每个对象，如果存在不匹配的情况，将其添加到一个新的数组中，并返回该数组。以下是一个示例代码：

// 定义两个对象数组
const arr1 = [
  {id: 1, name: "John", skills: [
    {name: "JavaScript", level: "advanced"},
    {name: "CSS", level: "intermediate"}
  ]},
  {id: 2, name: "Mary", skills: [
    {name: "HTML", level: "beginner"},
    {name: "Python", level: "intermediate"}
  ]},
  {id: 3, name: "Bob", skills: [
    {name: "Java", level: "advanced"}
  ]}
];

const arr2 = [
  {id: 1, name: "John", skills: [
    {name: "JavaScript", level: "advanced"},
    {name: "CSS", level: "beginner"}
  ]},
  {id: 2, name: "Mary", skills: [
    {name: "HTML", level: "beginner"},
    {name: "Python", level: "intermediate"}
  ]},
  {id: 4, name: "Alice", skills: [
    {name: "C#", level: "advanced"}
  ]}
];

// 使用reduce函数进行比较，并获取不匹配的对象数组
const unmatched = arr1.reduce((acc, cur, index) => {
  if (arr2[index] === undefined) {  // 如果arr2中不存在这个对象，则直接加到unmatched数组中
    acc.push(cur);
    return acc;
  }

  if (JSON.stringify(cur) !== JSON.stringify(arr2[index])) {  // 如果两个对象不一致，则加到unmatched数组中
    acc.push(cur);
  }

  const curSkills = cur.skills;
  const arr2Skills = arr2[index].skills;

  // 对两个对象中的skills数组进行比较
  curSkills.forEach(skill => {
    if (!arr2Skills.some(s => JSON.stringify(s) === JSON.stringify(skill))) {
      acc.push