Not sure if this is what you are looking for:
- Select any device in the Indigo UI
- Click the + sign in the bottom left.
This will create a new folder which you can rename.
You can rename/delete an existing folder by selecting it and then clicking the gear symbol in the bottom left. - Select the device in the main window (that you want to be in the new folder) and drag it to the folder name on the left-hand side.
The device will be moved to the folder and the folder name updated in the device
Hope this helps?