This makes sense, but I've been unable to implement the solution from that thread. I pasted the following code as a custom function, but I keep getting an error back.
void new_upd(int ID, list:string master_list, list:string bulk_list)
{
mod_data = for_check [ID == input.ID]; // fetches the record
for each item_1 in input.new_Lst
{
if (!input.master_list.contains(item_1)) // checks if the item isnt present in the list.
{
input.bulk_list.add(item_1); // adds item to list.
}
}
mod_data.All_Names = input.master_list; // updates the multi line field.
}