Search for usage of private nested types in declaring type

ILSpy/TreeNodes/Analyzer/ScopedWhereUsedAnalyzer.cs

@@ -128,7 +128,7 @@ namespace ICSharpCode.ILSpy.TreeNodes.Analyzer
 			DetermineTypeAccessibility();
 
 			if (typeAccessibility == Accessibility.Private) {
-				return FindReferencesInTypeScope(ct);
+				return FindReferencesInEnclosingTypeScope(ct);
 			}
 
 			if (memberAccessibility == Accessibility.Internal ||
@@ -237,6 +237,17 @@ namespace ICSharpCode.ILSpy.TreeNodes.Analyzer
 			}
 		}
 
+		private IEnumerable<T> FindReferencesInEnclosingTypeScope(CancellationToken ct)
+		{
+			foreach (TypeDefinition type in TreeTraversal.PreOrder(typeScope.DeclaringType, t => t.NestedTypes)) {
+				ct.ThrowIfCancellationRequested();
+				foreach (var result in typeAnalysisFunction(type)) {
+					ct.ThrowIfCancellationRequested();
+					yield return result;
+				}
+			}
+		}
+
 		private IEnumerable<AssemblyDefinition> GetReferencingAssemblies(AssemblyDefinition asm, CancellationToken ct)
 		{
 			yield return asm;