Groups in groups feature

[schwenno90]

Checklist

• I made sure that there are no existing issues - open or closed - to which I could contribute my information.
• I made sure that there are no existing discussions - open or closed - to which I could contribute my information.
• I have read the FAQs inside the app (Menu -> About -> FAQs) and my problem isn't listed.
• I have taken the time to fill in all the required details. I understand that the request will be dismissed otherwise.
• This issue contains only one feature request.
• I have read and understood the contribution guidelines.

Feature description

Add the feature to create groups in groups for better management.

Why do you want this feature?

It would be immensely helpful to be able to have a folder in folder structure for contacts, so I can sort and structure huge contact lists of my associations.

Additional information

For example I would love to be able to store contacts like this:

Business A:

• Export: Contact 1, Contact 2, ...
• IT: Contact 3, ...