How should I store page and subpage in collection with mongoose - node.js

Question

I'm trying to create simple CMS with the ability to add new pages to the site. I have currently created a Collection called Pages:
var PageSchema = new Schema({
name_en: {
type: String,
required: true
},
name_nl: {
type: String,
required: true
},
slug_en:{
type: String,
required: true
},
slug_nl:{
type: String,
required: true
},
content_en: {
type: String,
required: true
},
content_nl: {
type: String,
required: true
},
visible: {
type: Number,
required: true,
default: 1
},
is_headMenu: {
type: Number,
require: true,
default: 0
},
is_footerMenu: {
type: Number,
require: true,
default: 0
},
date: {
type: Date,
default: Date.now
}
});
This collection store all pages, but after a few days I needed to add an option to also store sub-pages to existing pages.
I was thinking of creating an object inside of the Page Schema to hold all the sub-pages.
Like this:
var subPage = new Schema({
name_nl: {
type: String,
required: true
},
name_en: {
type: String,
required: true
},
slug_en:{
type: String,
required: true
},
slug_nl:{
type: String,
required: true
},
content_en: {
type: String,
required: true
},
content_nl: {
type: String,
required: true
},
visible: {
type: Number,
required: true,
default: 1
}
});
var PageSchema = new Schema({
name_en: {
type: String,
required: true
},
name_nl: {
type: String,
required: true
},
slug_en:{
type: String,
required: true
},
slug_nl:{
type: String,
required: true
},
content_en: {
type: String,
required: true
},
content_nl: {
type: String,
required: true
},
visible: {
type: Number,
required: true,
default: 1
},
is_headMenu: {
type: Number,
require: true,
default: 0
},
is_footerMenu: {
type: Number,
require: true,
default: 0
},
subPages: [
subPage
],
date: {
type: Date,
default: Date.now
}
});
But I cant use it because after creating a Page I'm required to fill the object 'subPage' because it's required. I don't want that. I want to add them whenever I want, and this way its not possible. How should I do it properly?