[{
    "_id": 101,
    "name": "Computer",
    "Tags": ["B.Tech", "M.Tech", "BCA"],
    "details": "CollegeDept 1"
}, {
    "_id": 102,
    "name": "Mechanical",
    "domain_names": ["B.Tech", "M.Tech"],
    "details": "CollegeDept 2"

}
…
…
]

[{
        "_id": 1,
        "name": "Adam Smith",
        "enroll_dt": "2016-04-15T05:19:46 -10:00",
        "active": true,
        "last_login_at": "2013-08-04T01:03:27",
        "phone": "111-222-888",
        "signature": "Don't Worry Be Happy!",
        "dept_id": 101,
        "tags": [
            "B.Tech",
            "Computer"
        ]
    },
    {
        "_id": 2,
        "name": "Ron Dey",
        "enroll_dt": "2016-04-15T05:19:46 -10:00",
        "active": true,
        "last_login_at": "2013-08-04T01:03:27",
        "phone": "7080-656-878",
        "signature": "Don't Worry Be Happy!",
        "dept_id": 102,
        "tags": [
            "M.Tech",
            "Mechanical"
        ]
    }
]

"_id": 102,
    "name": "Mechanical",
    "domain_names": ["B.Tech", "M.Tech"],
    "details": "CollegeDept 2"

Student 2 : Ron Dey(and its details )