How to return value from an array of fields if the key name is stored in a variable?

Working with Data
1

Greetings. MongoDB version 4.4
I need to create a view that will display information in the desired form from all available collections. But in some fields the data is stored as objects, I need to parse the short ones.
I am trying to do this within a single view, but I am having a problem getting one value from this field

db.createView(
"testView",
"pasport_data",
[
    {
        $project: {
            _id: 0,
            "collection": "pasport_data",
            "record_date": 1,
            "record_table_id": 1,
            "record_customer_id": 1,
            "record_questionnaire_id": 1,
            "record_user_id": 1,
            "record_type": 1,
            "column": {$objectToArray: "$record_edit_column"},
            "record_value": 1,
        }
    },
    {
        $unwind: "$column"
    },
    {
        $project: {
            _id: 0,
            "collection": "pasport_data",
            "record_date": 1,
            "record_table_id": 1,
            "record_customer_id": 1,
            "record_questionnaire_id": 1,
            "record_user_id": 1,
            "record_type": 1,
            "column": "$column.k",
            "value_before": "$column.v",
            "value_after": "$record_value.$column.k",
        }
    }
]
)

Pay attention to the last line “value_after”: “$record_value.$column.k”. The problem is, I don’t know how to get this value. If, instead, I specify the name of the parameter I need, for example “value_after”: “$record_value.serial_p”, it returns the desired value to me. Otherwise, the view works.

Help me please