gistfile1.cs

var tree = CSharpSyntaxTree.ParseText(@"
  class MyClass
  class MyClass
  {
  	int myField1, myField2, myField3;
  }");

var Mscorlib = PortableExecutableReference.CreateFromAssembly(typeof(object).Assembly);
var compilation = CSharpCompilation.Create("MyCompilation",
syntaxTrees: new[] { tree }, references: new[] { Mscorlib });
var model = compilation.GetSemanticModel(tree);
var field = tree.GetRoot().DescendantNodes().OfType<FieldDeclarationSyntax>().Single();

foreach (var variable in field.Declaration.Variables)
{
	//Now we can access each of the symbols within the field
	var fieldSymbol = model.GetDeclaredSymbol(variable);
}