How can I create multiple user fields in a request offering form ?
Next, in the same form I need to add a Manager field and Contact field that are also users.
I don't need to select from a list, I just want the same behavior as the Affected User field in an incident template where you just type a few letters and then select the right name.
How can I do that ?
Out of the box this is not possible currently, but you could try using the ROToolbox , this will give similar functionality to the request on behalf of, for other user selections. The Toolbox can be found here
Make sure to test it thoroughly in your environment.