db={"orders":[{_id:1,restaurant_name:"Tea Place",drink:"tea"},{_id:2,restaurant_name:"Coffee Shop",drink:"tea"}],restaurants:[{_id:3,name:"Tea Place",beverages:["water","tea"]},{_id:4,name:"Coffee Shop",beverages:["coffee"]}]}

db.orders.aggregate([{$lookup:{from:"restaurants",localField:"restaurant_name",foreignField:"name",let:{drink:"$drink"},pipeline:[{$match:{$expr:{$in:["$$drink","$beverages"]}}}],as:"matches"}}])