The 'Job level' (or 'Business area' or 'Pay band') column contains information about the structure of your organisation. As such, we don't try to lay out specific terms you must use. Instead, we accept any text values in this field.
However, note that you must be consistent in how you label each person. Terms that are close but not identical will be treated separately within Umbrella. If you do find that this has happened, though, you can delete the initial dataset from within Umbrella, correct your spreadsheet and upload the new CSV file.