Mongo C# driver - Building filter dynamically with nesting

Builders is really flexible class, it also has overridden operators "& = AND" and "| = OR"

Your example will be

var filter = Builders<User>.Filter.Eq(x => x.A, "1");
filter &= (Builders<User>.Filter.Eq(x => x.B, "4") | Builders<User>.Filter.Eq(x => x.B, "5"));

You can use very simply like this way.....

var filter = Builders<Rental>.Filter.Where(s => s._id== id && s.Price==1500);