Accordion sidemenu from database

Ionic Framework ionic-v3
1

I used accordion side menu for my ionic project.but I have some issues,
in my ionic project, i have a JSON like this

[
  {
    "category":"Accessories & Moments",
    "subs": [
      {
        "subcategory":"'Watch Store"
      },
      {
        "subcategory":"Premium Fragments"
      },
      {
        "subcategory":"Confectioneries"
      }
    ]
  },
  {
    "category":"Kids Club",
    "subs": [
      {
        "subcategory":"'Watch Store"
      },
      {
        "subcategory":"Premium Fragments"
      }
    ]
  },
  {
    "category":"Women's Choice",
    "subs": [
      {
        "subcategory":"Red Moments"
      },
      {
        "subcategory":"Confectioneries"
      }
    ]
  }
]

i want to display it here

this.options.push({
      displayName: 'Accessories & Moments',
     subItems: [
       {
         displayName: 'Watch Store',
         component: subpage1
       }
      ]
    });

 ` displayName: 'Accessories & Moments',`

as this.sidemenus.subs and

 subItems: [
       {
         displayName: 'Watch Store',

as this.sidemenus.subs.subcategory
how can i do this
full code is here https://github.com/sebaferreras/Ionic3-MultiLevelSideMenu