I am trying to update the field names listed within my 'List Box' - the field names are pulling from a table loaded into our script. But I would like to overwrite the field names with an alias. Is this possible, without updating the source table? Can this be achieved by creating an Expression within the list box?
Do you mean field names that you see in a dropdown when you create a new listbox and have to choose which field is it going to show? If so, then you can not change those names in any way other than aliasing or renaming them in the datamodel. You don't have to change them in the source itself, just in the loadscript. One expedient way of doing that is through the "RENAME Using" statement.
As mentioned previously, I was able to successfully update the field names within my List Box but the field names are not flowing through to our Selection Box - is it possible to update the field names that appear there as well?
That's because you've changed only what is shown in one particular listbox without touching the underlying data. If you want to change it permanently, you will need to do it in the loadscript. One possible way is this: