[{"_id":"123456","name":"Bob","date":"2022-07-01","fruit":[{"_id":"000001","foodName":"apple","colour":"red"},{"_id":"000002","foodName":"apple","colour":"green"},{"_id":"000003","foodName":"banana","colour":"yellow"},{"_id":"000004","foodName":"orange","colour":"orange"}]}]

db.collection.aggregate([{$match:{"fruit.foodName":"apple"}},{$addFields:{fruit:{$filter:{input:"$fruit",cond:{$eq:["$$this.foodName","apple"]}}}}}])