Try this on a copy of a project first !
In Cubase:
Edit > Key Commands
search "Edit Info Line"
assign keys: alt+Shift+e
search "Insert and name Maker"
assign keys: alt+Shift+m
Select all the Cubase Chords and drag them to a midi track with snap enabled
make sure you have a maker track
select the first midi chord item
click the Cubase Chord Markers in Tab 2
WAIT ! for it to add the marker then click it again
File > Export > Midi File
Drag into BB Plugin.

See how it works for you, I allowed a bit of time between keystrokes, you can change delay with the Sleep value.
It will copy the Name from the info line top left above the inspector.
You may need to add 2 bars at the start for the BB Plugin and want the count-in, you will have to see how the chords line up in the BB Plugin.
I couldn't drag the midi file in from the Save dialog, so there should be an Import Chords from MIDI Markers in the C7 at the bottom added soon.

If you are running Biab As Administrator:
To run script only .ahk install https://www.autohotkey.com/ and set AutoHotKey.exe to Run As Administrator
To run .exe set to Run As Administrator
* remove .mp4 from file name and unzip
Download > BB Quick Menu & Mixer & Cubase Chords.zip.mp4