As far as at a specific retail location or store, there are:
Managers:
Store Manager
Assistant Manager
Grocery Manager
Customer Service Sales Manager
Assistant Customer Service Sales Manager
Manager of Produce
Meat Market Manager
Deli/Baker Manager
Frozen Food and Dairy Manager
Associates:
Sales Associates (Cashiers)
Service Associates (Baggers)
Grocery Associate (Stockers)
Office assistant
Scan Analyst
DSD Receivers
HBC Department
Produce Department
Meat Department
Deli/Bakery
FFD Department
Pet care departments
Wine and Beer Departments
Pharmacy
Security
That is in the store alone. However there are tons of other positions available in a grocery company that are not in one specific store (ie. Warehouse workers, truck drivers, district managers, CEO, president, marketing directors)
Manager
Usually they are called Baggers or Lot Attendants
a deli worker
Tech Person
a slave
Employee
someone who works for a business
A mathematician
hydrologist
moofer
A Chronogist
An astronomer.