After you add a user reference to a form, you can configure the way that users interact with it. For example, you can display the list of users in your application as a list or as an autocomplete that returns a list of search results.
In the navigation pane of Dev Studio, click Case types, and then click the case type that you want to open.
In the navigation pane of App Studio, click Case types, and then click the case type that you want to open.
On the Workflow tab, click Life cycle.
Click an assignment or an approval step.
Click Configure view.
Click the Gear icon in the row of the user-reference field.
Select a control type from the list that is displayed.
Search — Prompts users to search for an existing user by entering a full name or operator ID in an autocomplete field.
Dropdown — Prompts users to select the full name of an existing user from a list.
At run time, users are prompted to select or search for an existing user, based on the control type that you provide. The result, a user ID, is stored in the property that is associated with your user-reference field.