Amazon has an internal level structure that uses L5/L6/L7 all the way to L12 (Jeff Bezos).
In terms of the original question, in general, there is a daily limit to how much money you can spend on your business trip (per 24 hour each). At the end of your trip, you will need to request reimbursement to the company. However, there are set categories that you can or can not receive money back (example: baby sitting or getting dry cleaning service). As for flights, Amazon provides economy class only and you may upgrade on your own dime (but never using company expense).