db={"students":[{_id:67264264726476,name:"Student 1",email:"student1@email.com"}],"followups":[{_id:65536854685,student:67264264726476,message:"This is a student follow up"}]}

db.followups.aggregate([{"$lookup":{"from":"students",let:{s:"$student"},pipeline:[{"$match":{$expr:{$and:[{$eq:["$$s","$_id"]},{$or:[{"$in":["$name",["Student 1","Student 2"]]},{"$in":["$email",["student1@email.com","student2@email.com"]]}]}]}}}],"as":"student"}}])