Sure. Just add a bunch of expressions as the milti-box dimensions like:
If there are many more possibilities I would look at putting an Inline table in the script that matches the values to multi-box requirements, then having a more simple expression here.
Hope this helps,
I have a similar need. It works fine to display the items, however, I cannot select any values when a multibox field is an expression. It shows me the possible values but when I click on it, nothing is actually selected. If, instead of the expression, I add each one of the fields as separate fields It works but I can only show one or the other depending on my if check.