深层json数组、对象相互嵌套如何赋值？

Question

请问各位大神，代码如下，如何把4处的profData赋值给1处的profData，把3处的subjectData赋值给1处的subjectData？

        // 1
        treeData: [{
            qualName: '',
            qualCode: '',
            subjectData: [{
                subjectName: '',
                subjectCode: '',
                profData: [{
                    profName: '',
                    profCode: ''
                }]
            }
            ]
        }
        ],

        // 2
        qualData: [{ qualName: "工学", qualCode: "Q06" },
        { qualName: "理学", qualCode: "Q07" }]

        // 3
        subjectData: [{ subjectName: "计算机", subjectCode: "S01" }]

        // 4
        profData: [{ profName: "软件工程", profCode: "P01" }]