最终效果
点击 to test1

点击to test2  =>  to test21

点击to test2  =>  to test22

代码如下
 

          path: "page",element: <父组件 />,children: [{ path: "test1", element: <Test1 /> },{path: "test2",element: <Test2 />,children: [{ path: "test21", element: <Test21 /> },{ path: "test22", element: <Test22 /> },],},],

父组件如下 

   import { NavLink, Outlet } from "react-router-dom";    <div>I am 父组件<div><NavLink to="/en/page/test1"> to test1</NavLink></div><div><NavLink to="/en/page/test2"> to test2</NavLink></div><div style={{ marginLeft: "80px" }}><Outlet /></div></div>

test1组件

import React from "react";
const Test1 = () => {return <div> I am test1</div>;
};
export default Test1;

test2组件

import React from "react";
import { NavLink, Outlet } from "react-router-dom";const Test2 = () => {return (<div>I am test2{/* link */}<div><NavLink to="/en/apply/test2/test21"> to test21</NavLink></div><div><NavLink to="/en/apply/test2/test22"> to test22</NavLink></div><div style={{ marginTop: "60px" }}><Outlet /></div></div>);
};
export default Test2;

test21组件
​​​​​​​

import React from "react";
const Test21 = () => {return <div> I am test21</div>;
};
export default Test21;

test22组件

import React from "react";
const Test22 = () => {return <div> I am test22</div>;
};
export default Test22;