db={"Employees":[{"id":"001","name":"John"},{"id":"002","name":"Lisa"},{"id":"003","name":"Zery"},{"id":"004","name":"Nick"}],"Roles":[{"employee_id":"001","title":"software engineer"},{"employee_id":"001","title":"data scientist"},{"employee_id":"002","title":"data engineer"},{"employee_id":"002","title":"data scientist"},{"employee_id":"002","title":"data analyst"},{"employee_id":"003","title":"software engineer"}]}

db.Employees.aggregate([{"$lookup":{"from":"Roles","localField":"id","foreignField":"employee_id","as":"roles"}},{"$match":{"roles.title":{"$nin":["software engineer"]}}},{"$project":{"_id":0,"name":1}}])