**Title: MoI V5 CustomUI — Positioning category submenus correctly**

Hi,

I'm using MoI 3D V5 with CustomUI and have created a `ScriptsFull.menu.htm` menu that groups custom scripts into categories based on filename prefixes, such as `CRV_`, `SRF_`, `SOL_`, `SEL_` and `UTL_`.

The main Full Scripts flyout opens correctly to the left of its button, which is on the bottom toolbar.

However, when I select a category such as Curves, its submenu opens at the bottom-right of the screen rather than being positioned correctly alongside the main menu.

I'm currently calling:

```js
moi.ui.showMenu(
"moi://appdata/customui/" + file,
moi.ui.commandBar.CommandBarCustomUI,
1,
0
);
```

I've also tried `0, 0` and `3, 0`. These haven't resolved the positioning issue.

The original `Scripts.menu.htm` works as expected. Is there a way to anchor the category submenu to the Full Scripts menu item itself, or otherwise control its horizontal and vertical position?

I'd appreciate any guidance on the correct `showMenu()` arguments or the appropriate UI element to use as the anchor.

Thanks!