How to ignore null values for all source members during mapping in Automapper 6?

Method Condition now has five overloads, one of which accepts predicate of type

Func<TSource, TDestination, TMember, bool>

this TMember parameter is the source member. So you can check source member for null:

CreateMap<StatusLevelDTO, StatusLevel>()
     .ForAllMembers(opts => opts.Condition((src, dest, srcMember) => srcMember != null));