public class Company
{
    public string Id { get; set; }
    public string Name { get; set; }
    public IEnumerable<Department> Departments { get; set; }
}

public class Department
{
    public string Id { get; set; }
    public string Name { get; set; }
    public IEnumerable<Managers> Managers { get; set; }
}

public class Manager
{
    public string Id { get; set; }
    public string Name { get; set; }
    public IEnumerable<Employee> Employees { get; set; }
}

public class Employee
{
    public string Id { get; set; }
    public string Name { get; set; }
}

{
    "Id": 12345,
    "Name": "Company Ltd",
    "Departments": [
        {
            "Id": 1,
            "Name": "Development",
            "Managers" : [
                {
                    "Id" : 5555,
                    "Name" : "The Boss",
                    "Employees": [
                        {
                            "Id" : 123,
                            "Name" : "Developer 1"
                        },
                        {
                            "Id" : 124,
                            "Name" : "Developer 2"
                        }
                    ]
                }
            ]
        }
    ]
}