nameof autocompletion on nested class doesn't work for parent class members

Version Used: VS 15.5.5

Steps to Reproduce:

1. Create a nested class, like this:

class A
{
    string PropertyA { get; }

    class B
    {
        void MethodB()
        {
            Console.WriteLine(nameof(PropertyA)));
        }
    }
}

2. When typing nameof(P, PropertyA isn't shown as a suggestion, but the code compiles.

Expected Behavior: The code compiles and PropertyA is shown as suggestion.

Actual Behavior: The code compiles, but PropertyA isn't shown as suggestion.