Jinja to populate a List-User field via a Pipeline

I have a pipeline that when a record is created, it will search another table and if the project code matches in both tables, it needs to return a user value in one of the fields. However, there can be multiple records with the same project code but different user for each record. My pipeline finds the multiple records but is only returning one of the values in the List-User field. What is the jinja code to populate multiple 'user' values into the List-User field?

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Amy Gosz
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