Karsten’s answer is detailed, but I think you missed the fact that Field A and Field 1 are different Karsten.
In your naming I think this would be:
A and B and C and (X or Y or Z)
The answer is right though @geopartin - this is a rather frustrating limitation of the current tool. You can either do this:
A and B and C and X
OR
A and B and C and Y
OR
A and B and C and Z
or you can make a second list. I would definitely vote for the second list option as Karsten mentioned already. It’s a pain, but it’s actually not unhelpful to have sub-lists like this, not least because you can standardize the definition of something and then re-use it. And it prevents the gymnastics or trying to do the logic above.
@sharonlicari I was sure there was an Idea for this in the ideas forum to improve the conditional logic in lists. But I just searched and can’t for the life of me find it. Can you see if your search-fu is better than mine? We should all be upvoting that to improve this situation in the future 
This has caught me out before and had some slightly painful business implications when I messed it up!
Cheers,
Mike