I don’t know if I just got lucky or if I found a solution. I went to the Engrave page and tried different things. Then, after selecting the ‘4’ and dragged it, both of the notes appeared in the tablature. I’ll see if I can find a way to separate the B notes too.
However, I can’t find a way to separate the notes to appear clearly as two different voices, like in the original score.
This is the closest I’ve been able to do to get what I want to achieve. I was able to add another fingering ‘0’ and move it upwards and to the right. This would be easy to fix if I could show only the voice I want to edit. But hiding voices is not supported as far as I know.