db={"categories":[{"_id":"6436785542e668cd2f20e42d","title":"Phones","children":["64367a2942e668cd2f20e42f","64367b0942e668cd2f20e430","64367b0942e668cd2f20e431","64367b0942e668cd2f20e432","64ad39a8fed1077091989e46"],"filters":["6436a09e62272f5f7a07522c","6436a09e62272f5f7a07522d","6436a09e62272f5f7a07522e"]}],"filters":[{"_id":"6436a09e62272f5f7a07522c","filterType":"checkbox","title":"Year","targetProperty":"year"},{"_id":"6436a09e62272f5f7a07522d","filterType":"checkbox","title":"Model","targetProperty":"model"},{"_id":"6436a09e62272f5f7a07522e","filterType":"checkbox","title":"Memory","targetProperty":"memory"}],"products":[{"_id":"64369a9162272f5f7a075215","name":"iPhone 11 Pro Max","pathname":"phones/iphone/11-pro-max/iphone-11-pro-max","categories":["6436785542e668cd2f20e42d","64367a2942e668cd2f20e42f","64367dfe42e668cd2f20e436"],"variations":[{"_id":"658bde58ab378aedc4c4fa8a","name":"512 GB Midnight Green","price":42900,"available":2,"details":{"memory":{"title":"Память","value":"512 GB"}}},{"_id":"658bde58ab378aedc4c4fa8d","name":"128 GB Gold","price":36900,"available":14,"details":{"memory":{"title":"Memory","value":"128 GB"}}}],"details":{"model":{"title":"Модель","value":"11 Pro Max"},"year":{"title":"Год","value":2019},"processor":{"title":"Процессор","value":"A13 Bionic"}}}]}

db.categories.aggregate([{"$lookup":{"from":"filters","localField":"filters","foreignField":"_id","as":"filters","let":{"category_id":"$_id"},"pipeline":[{"$lookup":{"from":"products","let":{"target_property":"$targetProperty"},"as":"options","pipeline":[{"$match":{"$and":[{"$expr":{"$in":["$$category_id","$categories"]}},{"$expr":{"$or":[{"$ne":[{"$getField":"details.$$target_property"},null]},{"$ne":[{"$getField":"variations.details.$$target_property"},null]}]}}]}},{"$unwind":{"path":"$variations","preserveNullAndEmptyArrays":true}},{"$group":{"_id":{"$ifNull":[{"$getField":"details.$$target_property.value"},{"$getField":"variations.details.$$target_property.value"}]}}},{"$group":{"_id":null,"options":{"$push":"$_id"}}},{"$project":{"_id":0}}]}}]}}])