If you are using the word to refer to people who work in the same organisation, then, you generally use “staff” and not “staffs”. The word “staff” can be followed by a singular or a plural verb.
*The staff have decided not to accept the offer made by the government. *I understand that the staff is terribly worried about the on-going strike.
An individual who works for an organisation is referred to as “member of staff”.
*Atul expects every member of staff to be present at the meeting.
The word “staffs” is being used both in British and American English to refer to more than one group of people — individuals working for different organisations.
*The minister and his staff were present at the meeting. *The two ministers and their staffs were present at the meeting.