CODE EXAMPLE FOR JAVASCRIPT

find only duplicate data javascript object

const data = [{id: 1, order_id: 1}, {id: 2, order_id: 1}, {id: 3, order_id: 2}]
const duplicates = data.filter((item, index) => 
index !== data.findIndex((v) => v.order_id === item.order_id));

console.log(duplicates)