Well, there are more functions supported by the logic protocol than you have buttons/inputs on your midibox. If you want these funcions anyway you have different layers, which means that you assign more than one function to a single button. Most suitable you put the functions which are less important in your personal workflow to the second layer. There might also be some Midibox-specific functions which I would also put to another layer.
The “clou” now is that you choose a button on your box and assign the MBLC_HOLD_LAYER function to this input. You can now switch through the different layers. Alternatively you can have a configuration which lets you access second-layer functions while holding this button (similar to an “alt” function).