fix: show inherited persistent flags in command help

command.go

@@ -300,18 +300,21 @@ func (cmd *Command) appendFlag(fl Flag) {
 	}
 }
 
-// VisiblePersistentFlags returns a slice of [LocalFlag] with Persistent=true and Hidden=false.
+// VisiblePersistentFlags returns inherited persistent flags with Hidden=false.
 func (cmd *Command) VisiblePersistentFlags() []Flag {
 	if cmd.isCompletionCommand {
 		return nil
 	}
 	var flags []Flag
-	for _, fl := range cmd.Root().Flags {
-		pfl, ok := fl.(LocalFlag)
-		if !ok || pfl.IsLocal() {
-			continue
+	lineage := cmd.Lineage()
+	for i := len(lineage) - 1; i > 0; i-- {
+		for _, fl := range lineage[i].allFlags() {
+			pfl, ok := fl.(LocalFlag)
+			if !ok || pfl.IsLocal() {
+				continue
+			}
+			flags = append(flags, fl)
 		}
-		flags = append(flags, fl)
 	}
 	return visibleFlags(flags)
 }

help_test.go

@@ -858,6 +858,52 @@
 	assert.Contains(t, output.String(), expected, "expected output to include global options")
 }
 
+func TestShowNestedSubcommandHelp_InheritedPersistentFlags(t *testing.T) {
+	cmd := &Command{
+		Flags: []Flag{
+			&StringFlag{
+				Name:  "root-persistent",
+				Local: false,
+			},
+		},
+		Commands: []*Command{
+			{
+				Name: "mid",
+				Flags: []Flag{
+					&StringFlag{
+						Name:  "mid-persistent",
+						Local: false,
+					},
+					&StringFlag{
+						Name: "mid-local",
+						Local: true,
+					},
+				},
+				Commands: []*Command{
+					{
+						Name: "leaf",
+						Flags: []Flag{
+							&StringFlag{Name: "leaf-local"},
+						},
+					},
+				},
+			},
+		},
+	}
+
+	output := &bytes.Buffer{}
+	cmd.Writer = output
+
+	_ = cmd.Run(buildTestContext(t), []string{"root", "mid", "leaf", "--help"})
+
+	assert.Contains(t, output.String(), "GLOBAL OPTIONS:",
+		"expected help to include a global options section")
+	assert.Contains(t, output.String(), "--root-persistent string",
+		"expected help to include the root persistent flag")
+	assert.Contains(t, output.String(), "--mid-persistent string",
+		"expected help to include the intermediate persistent flag")
+}
+
 func TestShowSubcommandHelp_GlobalOptions_HideHelpCommand(t *testing.T) {
 	cmd := &Command{
 		Flags: []Flag{