You can join two or more values in CommCare using "concatenate."
Create a hidden value that joins together the items- for example item1, item2, item3
This example of the concatenate function takes a "first name" and "surname" and puts them into a value called #form//fullname. The quotations ' ' put a space between the two values. This would output a name as "John Snow" instead of "JohnSnow."