[JoeBaggins]

The best way I have found is to move all of a certain type of book onto your Onyx device at once. For instance, I group certain books by author and other books by tags. To bulk organize them on my Onyx Nova2 I follow these steps:

1. Filter books in Calibre to a specific author or tag
2. Transfer all of that specific author or tag onto your Onyx device
3. In the NeoReader section of your Onyx device, in the upper right hand corner, choose the icon that looks like a check mark in a box
A. Because your Onyx device allows you to make changes to the device
while it is plugged into your computer you don't have to disconnect your
ereader for this step
4. On the navigation bar on the left hand side of your Onyx device, choose select all (You will know they have all been selected by looking at the bottom of your ereader screen)
5. Next, on the navigation bar on the left hand side of your Onyx device, choose Move
6. A box will appear with all of the different folders/subgenres you have created, if you haven't created any (of if you need to add a new one) the box has an option to add a folder. I created folders/subgenres that mirror the authors or tags in Calibre I set up.

Hopefully this helps!