DS 260 need help in filling "Previous Work" part

[Sergey_TA]

Good day.
May I have some help with a few questions about "Previous Work/Education/Training Informatio" part of DS-260?

1. During work in one company I have changed several positions (was promoted). Do I have to show it in DS-260?
2. Employment Date From - Is this point mean hiring date or date of promotion?
3. Supervisor’s Surname- Is this point nessesary? I mean ... I changed a lot of jobs during last 12 years. I just don't remember all theese guys' names and surnames.

Thanks in advance and have a nice day.