Array of objects within array of objects

I'm fairly new to Java and I'm having a bit of trouble completing an assignment.

We are asked to create a program that takes information from companies (we are supposed to create at least three). From each company we have to enter the number of departments, from each department the number of employees, from each employee the projects assigned and whether if the project is completed or not. We were told as a hint that the departments are not subclasses but rather properties.

I've so far created a class that creates the companies but I'm stuck on how to do next...

I was thinking on creating an array of department objects of some sort then another array for employees, Am I heading in the right direction?

class Company{

    String companyName;
    int numberOfDepartments;      

    Company (String companyName, int numberOfDepartments){
        this.companyName= companyName;
        this.numberOfDepartments = numberOfDepartments;
    }

    void message(){
        System.out.print (companyName + " has " + numberOfDepartments + " Departments ");
    }

    public static void main (String [] args){
        Company myCompany= new Company("myCompany", 10);
        myCompany.message();
    }
}

Any help will be appreciated.