How to get value in single array extracted from nested array only through map function

How to get value in single array not in nested array without any additional operation outside map function.

const List = []
List.push(
    {
        name: 'John',
        id: 383,
        Value: [
            {
                "Age": "10"
            },
            {
                "Age": "20"
            }
        ],
    },
    {
        name: 'Mark',
        id: 545,
        Value: [
            {
                "Age": "30"
            },
            {
                "Age": "40"
            }
        ],
    }
)

const ageList = List.map((list, index) => {

    let age = [];
    list.Value.map(item => {
        age.push(item.Age)
    })
    return age
})
console.log(ageList)

Orignal Output : [ [ ’10’, ’20’ ], [ ’30’, ’40’ ] ]
Expected Output : [10,20,30,40]