db={companiesCollection:[{_id:ObjectId("627d0abab8a37f9c32fd6ad7"),name:"Acme"}],licensesCollection:[{_id:ObjectId("627d0abab8a37f9c32fd6ad8"),companyId:ObjectId("627d0abab8a37f9c32fd6ad7"),userId:ObjectId("627d0abab8a37f9c32fd6ad0")},{_id:ObjectId("627d0abab8a37f9c32fd6ad9"),companyId:ObjectId("627d0abab8a37f9c32fd6ad7"),userId:ObjectId("627d0abab8a37f9c32fd6ad1")}],usersCollection:[{_id:ObjectId("627d0abab8a37f9c32fd6ad0"),companyId:ObjectId("627d0abab8a37f9c32fd6ad7")},{_id:ObjectId("627d0abab8a37f9c32fd6ad1"),companyId:ObjectId("627d0abab8a37f9c32fd6ad7")},{_id:ObjectId("627d0abab8a37f9c32fd6ad2"),companyId:ObjectId("627d0abab8a37f9c32fd6ad7")},{_id:ObjectId("627d0abab8a37f9c32fd6ad3"),companyId:ObjectId("627d0abab8a37f9c32fd6ad7")},]}

db.usersCollection.aggregate([{$lookup:{from:"licensesCollection",localField:"_id",foreignField:"userId",as:"licensedUsers"}},{$match:{"licensedUsers.0":{$exists:false}}},{$group:{_id:"$companyId",unlicensedUsers:{$push:{_id:"$_id",companyId:"$companyId"}}}},{$lookup:{from:"companiesCollection",localField:"_id",foreignField:"_id",as:"company"}},{$project:{unlicensedUsers:1,company:{"$arrayElemAt":["$company",0]}}},{$project:{unlicensedUsers:1,name:"$company.name"}}])