JSFiddle - React, Tailwind, and code Playground

JavaScript

var product = {
    "prduct_name": "Mobile",
    "product_attribute": {
        "attribute_name": "Brand",
        "type": "combo",
        "product_attribute_values": {
            "attribute_value": "Apple",
            "brand_price": "2000"
        }
    }
};

function printData(data) {
    var str = '';
    for (var key in data) {
        if (typeof data[key] == 'object') str += key + printData(data[key]) + ' ';
        else str += key + ' => ' + data[key] + ' ';
    }
    return str;
};

console.log(printData(product));