Hi,

creating something like [BsonKnownTypes] and [BsonDiscriminator] Attributes to configure Nested Objects is one of essential features that should be available in EF Core MongoDB Provider.

Code Example:

{{}}

public class TempDocument 
{
    public ParentType Type {get; set;} 
}
public class ParentType 
{ 
    // properties 
} 
public class TypeA: ParentType 
{ 
    // properties 
} 
public class TypeB: ParentType
{
    // properties 
}

{{}}

ParentType, TypeA and TypeB classes need a new feature to be configured in (DatabaseContext class // OnModelCreating method).