JSFiddle - React, Tailwind, and code Playground

HTML

<div id='JSONOutput'></div>

JavaScript

var oldJSON = [{
  "categories":"Food",
  "subcategories":"Shares",
  "pid":"111",
  "title":"Smoked Salmon Dip",
  "description":"Rich and savory salmon dip, whipped with fresh dill accompanied with     croustades"
   },
   {
  "categories":"Food",
  "subcategories":"Shares",
  "pid":"112",
  "title":"Sweet Goat Cheese Flatbread",
  "description":"Delicate grilled Naan flatbread coated with delish tomato jam and topped with melted goat cheese, roasted garlic, fennel, onion, pear, shiitake mushroom and arugula."
 },
 {
  "categories":"Food",
  "subcategories":"Snacks",
  "pid":"100",
  "title":"Beer Chili",
  "description":"Hot & satisfying short rib chili with black beans, smoked jalapenos, and fresh corn. Topped with aged cheddar cheese and sour cream."
 }];


Object.prototype.groupBy = function(itemName, preGrouped)
{
    if(preGrouped)
    {
        for(prop in this)
        {
            if(typeof(this[prop]) === 'object' && this[prop].groupBy !== undefined)
            {
                var reGroup = this[prop].groupBy(itemName);  
                this[prop] = reGroup;
            }
        }
        return this;
    }
    else
    {
        var uniqueItems = {};
        var uniqueItemLength = 0;
        for(var i=0, length=this.length; i < length; i++)
        {
           var item = this[i]; 
           var z =0;
           var found = false;
           while(z < uniqueItemLength)
           {     
               if(item[itemName] in uniqueItems)
               {
                   uniqueItems[item[itemName]].push(item);
                   found = true;
                   break;
               }
               z++;
           }
            if(!found)
            {
                uniqueItems[item[itemName]] = [];
                uniqueItems[item[itemName]].push(item); 
                uniqueItemLength++;
            }      
        }
        return uniqueItems;
    } 
}

//Run conversion on object
var convertedData =...