let arr = [

        {

          Category:'A',

          Amount:,

        },{

          Category:'B',

          Amount:,

        },{

          Category:'A',

          Amount:,

        },{

          Category:'C',

          Amount:,

        },{

          Category:'B',

          Amount:,

        },{

          Category:'C',

          Amount:,

        },{

          Category:'A',

          Amount:,

        },{

          Category:'C',

          Amount:,

        }

      ];

      let temp = {};

      let end = [];

      for(let i = ; i < arr.length; i++){

        let a = arr[i];

        if(!temp[a.Category]){

          end.push({

            Category: a.Category,

            data: [a]

          });

          temp[a.Category] = a;

        }else{

          for(let j = ; j < end.length; j++){

            let b = end[j];

            if(b.Category == a.Category){

              b.data.push(a);

              break;

            }

          }

        }

      };

      console.log(end);