c# - How do you add multiple elements in a list at once or with a loop?

I am trying to add a non-constant value of elements by either looping through x times or just adding x nr of elements directly.

I've tried looping for x amount of times and add an element every iteration, but it only ends up with one element. I've also tried adding a collection, but the same result occurred.

using System.Collections;
using System.Collections.Generic;
using System.Linq;
using UnityEngine;



public class tileMapDepth 
{
    public List tileMapWidth;


    public tileMapDepth(List realWidth)
    {
        this.tileMapWidth = realWidth;
    }
}

public class TestListTypeAndSuch : MonoBehaviour
{


    public List tileMap = new List(1);
    public int width = 5;
    public int depth = 5;

    void Start()
    {
        for (int i = 0; i < depth; i++)
        {
            tileMap.Add(new tileMapDepth(new List(new List(width))));
            foreach (tileMapDepth tile in tileMap)

            {
                for (int j = 0; j < width; j++)
                {
                    tile.tileMapWidth.Add(false);
                }
            }
        }
    }
}

The expected result is to add a nr of elements into a list and not just one element.
When i try and add booleans with a constant value as the amount it works fine. But i need to add it with a dynamic variable. The code below is the only one that is working.

        for (int i = 0; i < depth; i++)
        {
            tileMap.Add(new tileMapDepth(new List(new List(new bool[13]))));
        }