[{"attributes":[{"basicDetails":[{"name":"Name","fieldType":"textField","fieldKey":"nameField","fieldDependendent":"","valueString":"","valueArray":"","valueBoolean":false},{"name":"Address","fieldType":"textareaAddressField","fieldKey":"addressField","fieldDependendent":"","valueString":"this address","valueArray":"Test","valueBoolean":false}],"specificationDetails":"","additionalDetails":""}],"status":"","createdAt":"","updatedAt":""}]

db.collection.update({},[{$set:{address:{$arrayElemAt:[{$arrayElemAt:["$attributes.basicDetails.valueString",0]},1]}}}],{multi:true})