[{/**_id: ObjectId("63608e3c3b74ed27b5bdf703"),*/placename:"khulna",frnds:[{name:"osama",cost:"2121"},{name:"lotid",cost:"2121"},{name:"haris",cost:"2121"},{name:"atiq",cost:"2121"},],},{/**_id: ObjectId("63608e3c3b74ed27b5bdf703"),*/"plmarshal":"narishal",frnds:[{name:"ojda",cost:"2121"},{name:"majid",cost:"2121"},{name:"nafis",cost:"2121"},{name:"rofiq",cost:"2121"}],},{/**_id: ObjectId("63608e3c3b74ed27b5bdf703"),*/placename:"latin america",frnds:[{name:"mamun",cost:"2121"},{name:"lotifa",cost:"2121"},{name:"sajid",cost:"2121"},{name:"natiq",cost:"2121"}],}]

db.collection.update({"placename":"khulna","frnds.name":"osama"},{$set:{"frnds.$[f]":{name:"rasana",cost:"212871"}}},{arrayFilters:[{"f.name":"osama"}]})