[{"_id":"abcd","basePrice":5000,"productCategories":[{"_id":"dsfsdfsd","categoryName":"","isActive":true,"products":[{"_id":"dererer","productCode":"GoKart","price":5000}]}]},{"_id":"abcd2","basePrice":4000,"productCategories":[{"_id":"dsfsdfsd2","categoryName":"","isActive":true,"products":[{"_id":"dererer","productCode":"GoKart","price":5000}]}]}]

db.collection.aggregate([{$match:{"productCategories.isActive":true}},{$unwind:{path:"$productCategories",preserveNullAndEmptyArrays:true}},{$unwind:{path:"$productCategories.products",preserveNullAndEmptyArrays:true}},{$match:{$expr:{$eq:["$basePrice","$productCategories.products.price"]}}}])