Index: clang/docs/ReleaseNotes.rst
===================================================================
--- clang/docs/ReleaseNotes.rst
+++ clang/docs/ReleaseNotes.rst
@@ -293,6 +293,9 @@
   and Clang 15 accidentally stopped predeclaring those functions in that
   language mode. Clang 16 now predeclares those functions again. This fixes
   `Issue 56607 <https://github.com/llvm/llvm-project/issues/56607>`_.
+- Fix an issue about ``decltype`` in the members of class templates derived from
+  templates with related parameters.
+  `Issue 58674 <https://github.com/llvm/llvm-project/issues/58674>`_
 
 Improvements to Clang's diagnostics
 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
@@ -781,8 +784,8 @@
 - Introduced the new function ``clang_CXXMethod_isCopyAssignmentOperator``,
   which identifies whether a method cursor is a copy-assignment
   operator.
-- ``clang_Cursor_getNumTemplateArguments``, ``clang_Cursor_getTemplateArgumentKind``, 
-  ``clang_Cursor_getTemplateArgumentType``, ``clang_Cursor_getTemplateArgumentValue`` and 
+- ``clang_Cursor_getNumTemplateArguments``, ``clang_Cursor_getTemplateArgumentKind``,
+  ``clang_Cursor_getTemplateArgumentType``, ``clang_Cursor_getTemplateArgumentValue`` and
   ``clang_Cursor_getTemplateArgumentUnsignedValue`` now work on struct, class,
   and partial template specialization cursors in addition to function cursors.
 
Index: clang/lib/Sema/SemaExpr.cpp
===================================================================
--- clang/lib/Sema/SemaExpr.cpp
+++ clang/lib/Sema/SemaExpr.cpp
@@ -2693,19 +2693,28 @@
   // spuriously dependent expression if we're inside a dependent
   // instance method.
   if (!R.empty() && (*R.begin())->isCXXClassMember()) {
-    bool MightBeImplicitMember;
-    if (!IsAddressOfOperand)
-      MightBeImplicitMember = true;
-    else if (!SS.isEmpty())
-      MightBeImplicitMember = false;
-    else if (R.isOverloadedResult())
-      MightBeImplicitMember = false;
-    else if (R.isUnresolvableResult())
-      MightBeImplicitMember = true;
-    else
-      MightBeImplicitMember = isa<FieldDecl>(R.getFoundDecl()) ||
-                              isa<IndirectFieldDecl>(R.getFoundDecl()) ||
-                              isa<MSPropertyDecl>(R.getFoundDecl());
+    bool MightBeImplicitMember = true, CheckField = true;
+    if (IsAddressOfOperand) {
+      MightBeImplicitMember = SS.isEmpty() && !R.isOverloadedResult();
+      CheckField = !R.isUnresolvableResult();
+    }
+    if (MightBeImplicitMember && CheckField) {
+      if (R.isSingleResult() &&
+          isa<FieldDecl, IndirectFieldDecl, MSPropertyDecl>(R.getFoundDecl())) {
+        if (auto Class = dyn_cast_if_present<CXXRecordDecl>(
+                (*R.begin())->getDeclContext())) {
+          for (auto Curr = S->getLookupEntity(); Curr && !Curr->isFileContext();
+               Curr = Curr->getParent()) {
+            if (auto ThisClass = dyn_cast_if_present<CXXRecordDecl>(Curr)) {
+              if ((MightBeImplicitMember = ThisClass->Equals(Class) ||
+                                           ThisClass->isDerivedFrom(Class)))
+                break;
+            }
+          }
+        }
+      } else if (IsAddressOfOperand)
+        MightBeImplicitMember = false;
+    }
 
     if (MightBeImplicitMember)
       return BuildPossibleImplicitMemberExpr(SS, TemplateKWLoc,
Index: clang/test/SemaCXX/decltype.cpp
===================================================================
--- clang/test/SemaCXX/decltype.cpp
+++ clang/test/SemaCXX/decltype.cpp
@@ -101,6 +101,44 @@
   template<class T> void foo(decltype(T(LP1{ .p1 = g1, .p1.x[1] = 'x' }))) {}
 }
 
+namespace GH58674 {
+  struct Foo {
+    float value_;
+    struct nested {
+      float value_;
+    };
+  };
+
+  template <typename T>
+  struct TemplateFoo {
+    float value_;
+  };
+
+  float bar;
+
+  template <typename T>
+  struct Animal{};
+
+  template <typename T>
+  class Cat : Animal<T> {
+    using okay = decltype(Foo::value_);
+    using also_okay = decltype(bar);
+    using okay2 = decltype(Foo::nested::value_);
+    using okay3 = decltype(TemplateFoo<T>::value_);
+  public:
+    void meow() {
+      using okay = decltype(Foo::value_);
+      using also_okay = decltype(bar);
+      using okay2 = decltype(Foo::nested::value_);
+      using okay3 = decltype(TemplateFoo<T>::value_);
+    }
+  };
+
+  void baz() {
+      Cat<void>{}.meow();
+  }
+}
+
 template<typename>
 class conditional {
 };