```ts
type AriaSubMenu = object & 
  | {
  items: AriaMenuItem[];
  content?: never;
}
  | {
  content: React.ReactNode | (helpers) => React.ReactNode;
  items?: never;
};
```

A submenu that opens in place inside an [AriaMenu](../variables/AriaMenu.mdx) when its parent item
is clicked. A submenu can either render a nested list of [AriaMenuItem](AriaMenuItem.mdx)
(which can themselves open further submenus) or arbitrary React content. When
a submenu is open, a back button is rendered at the top of the menu to return
to the previous level.

## Type Declaration

| Name | Type | Description |
| ------ | ------ | ------ |
| `title?` | `React.ReactNode` | Optional title shown next to the back button at the top of the submenu. |
| `titleTestId?` | `string` | The test id applied to the submenu title. |
| `testId?` | `string` | The test id applied to the submenu container. |
| `backButtonLabel?` | `string` | Aria label for the back button rendered at the top of the submenu. Overrides the menu-level `backButtonLabel`. |
| `backButtonTestId?` | `string` | The test id for the back button rendered at the top of the submenu. |