To add phone numbers to a list, while editing the list, go to:
  1. Select Objects
  2. Expand Constituent Information on the lefthand side
  3. Select User Phone
  4. From the Select Parent pop-up, select the appropriate User Base.User ID
  5. Display Fields
  6. Select Fields
  7. Expand User Base
  8. Find and expand User Phone
  9. Select Phone Number
  10. Select
  11. Save