Searching across the internet how to retrieve a subset of fields in MongoDB, using C# official driver (but using LinQ as the base architecture) I found how to do this in Mon
The driver does not currently retrieve a subset of the fields. If you need that functionality, you'll need to do it manually. The ticket for this functionality is here: https://jira.mongodb.org/browse/CSHARP-456. Feel free to leave feedback or vote it up if you need this.