I am trying to build in a process definition to update a number of fields with particular values based on the present of a value in one field. The issue I'm running into is updating a field that is multi-select to include the new value without erasing the current value. My process definition is pretty straight forward and work on update the four fields i need updated but it erases the existing value in a multi-select field that i would like to preserve. Is there a way for the process definition to add values in the case of a multi-select field?