JSFiddle - React, Tailwind, and code Playground

JavaScript

var data = {
  "model_A": [
    {
      "col_1": "Article A",
      "col_2": "description A",
      "model_B": {
        "col_3": "/imageA.jpg"
      },
      "model_C": [
      	{
        	"col_4": "tag1",
          "col_5": 3
      	},
        {
        	"col_4": "tag2",
          "col_5": 4
      	},
      ]
    },
    {
      "col_1": "Article B",
      "col_2": "description B",
      "model_B": {
        "col_3": "/imageB.jpg"
      },
    }
  ]
}

console.log(data)


var convertedData = convert(data);

function convert(data) {

}

var expectedData = [
  [
    "Article A",
    "description A",
    "/imageA.jpg",
    "tag1",
    3
  ],
  [
    "Article A",
    "description A",
    "/imageA.jpg",
    "tag2",
    4
  ],
  [
    "Article B",
    "description B",
    "/imageB.jpg",
    "",
    ""
  ],
]

console.log(expectedData)