我在一个json文件中有一个对象数组：

[
  {
    "department": "Sound Department",
    "subDepartments": [
      "Supervising Sound Editor",
      "Dialog Editor",
      "Sound Designer",
      "Foley Artis",
      "Sound Recordist"
    ]
  },
  {
    "department": "Camera Department",
    "subDepartments": [
      "Camera Operator",
      "Second Assistant Camera",
      "Other Assistant Camera",
      "Steadycam Operator",
      "Focus Puller"
    ]
  },
  {
    "department": "Production Department",
    "subDepartments": [
      "Camera Operator",
      "Second Assistant Camera",
      "Other Assistant Camera",
      "Steadycam Operator",
      "Focus Puller"
    ]
  }
]

从这里我创建了一个部门下拉菜单。从这里我想创建另一个子部门下拉菜单的基础上，哪个部门已被选中。
Departments的下拉菜单工作正常，也可以将该部门存储在一个状态中。我只是不知道如何过滤这些内容。

import React, { useState } from "react";
import "./CreateJobPage3.css"

import Button from "../Input/Button";
import Select from "../Input/Select";
import departmentData from "../Data/departmentSheet.json";

const CreateJobPage3 = (props) => {
    const [department, setDepartment] = useState()
    const [subDepartment, setSubDepartment] = useState()

    const departments = departmentData.map((data) => data.department)

    const subDepartments = departmentData.filter(item => {
        return item.department === department;
      });

    const departmentHandler = (props) =>{
        setDepartment(props)
    }

    const subDepartmentHandler = (props) =>{
        setSubDepartment(props)
    }

  return (
    <>
      <div className="CJP3___inner">
          <Select
            placeholder="Choose Department"
            options={departments}
            value={department}
            onChangeOption={departmentHandler}
          />
          <Select
            placeholder="Choose Department"
            options={subDepartments}
            value={subDepartment}
            onChangeOption={subDepartmentHandler}
            isMulti={true}
          />
      </div>
      <Button className="isGrey formButton" text={"Add Function"} />
    </>
  );
};

export default CreateJobPage3;