Possibility to create sub-panels (sub-GUIs) for /is settings

[mikenex10]

Is your feature request related to a problem?

I want to create a parent-flag for cosmetics (ProCosmetics plugin) for allowing users to manage which users can use cosmetics in their islands. I can create a separate flag for every single cosmetic type but that would result in 8-10 different flags.

It would be awesome to be able to create a "parent flag" (just like COMMAND_RANKS flag) that opens a GUI when you click on it and shows there another list of "sub-flags" related to the parent one.

For example: I would create a parent flag (COSMETICS) which opens a GUI when left-clicked. In this GUI the player could manage some different "subflags" (COSMETICS_BALLOONS, COSMETICS_MOUNTS, COSMETICS_MORPHS...) individually.

Describe the solution you'd like.

An option to create this kind of "sub-GUI" for a flag, using the API.

Describe alternatives you've considered.

The only alternative is actually to have those sub-flags distributed along the main settings menu, but that's not so "user-friendly" since you need to search for every single flag through the settings menu.

Agreements

• I have searched for and ensured there isn't already an open issue regarding this.
• I have ensured the feature I'm requesting isn't already in the latest supported BentoBox build or Addons.

Other

No response