I have a custom field. Type is LIST and the list is VENDOR. When I add the field to the form, is there any simple way to make it display another field on the vendor record (specifically in this case, their {companyname} instead of their {entityid})?

You'd want a free-text field and then source the value into the field either via field sourcing (uncheck store value on the field). You can also use the id directly in the defaulting tab if the sourcing isn't directly available. You put the ID in brackets like you have: {companyname} in the defaulting tab which will check the "formula" box.

I think I may not have presented my question properly. I want the list of vendors that the end user chooses from to be the companyname instead of the entityid. Same with like an item list/multi-select. They're seeing ITEM IDs and I'd like them to see the display name.

Hi Jessica. I have not found a way to do this. Essentially all list values use the record “name” field when displayed in the list I have not found a way to display a different field in the list to make it easier to read I think this is because NetSuite provides validation to make sure there are not duplicate values in the name field so your list always has unique values