UpdateDictionary

[Button("Update List")]
    public void UpdateDictionary()
    {
        ref var data = ref GetData(out _);
        var dictionary = data.UpdateAtLevel;
        // Create values
        if(dictionary.Count == 0)
        {
            foreach (Transform child in transform)
            {
                dictionary.Add(child.GetSiblingIndex(), child.gameObject);
            }
        }
        // Add new values
        else if(transform.childCount > dictionary.Count)
        {
            for (int i = transform.childCount - (transform.childCount - dictionary.Count); i < transform.childCount; i++)
            {
                dictionary.Add(dictionary.Keys.Last() + 1, transform.GetChild(i).gameObject);
            }
        }
        // Remove null values
        else if(transform.childCount < dictionary.Count)
        {
            var nullValues = new List<int>();
            // get null values
            foreach (var item in dictionary)
            {
                if(item.Value.Equals(null))
                {
                    nullValues.Add(item.Key);
                }
            }
            // remove 'em
            foreach (var item in nullValues)
            {
                dictionary.Remove(item);
            }
        }
    }