For general information on sheets, see Using Sheets.
Levels in your model may have different currencies. Your admin can choose different currencies for each level. When you enter data, you enter data in the currency of the level.
If you have access to multiple levels, check the currency at the bottom right corner of your screen:
When levels are not in the rows, the sheet displays the currency of the level you select from the 1 toolbar drop-down of modeled and standard sheets, or the 2 level filter of cube sheets. See Identify Sheets Types.
When levels with different currencies are in the rows, the data displays in the currency of the top-most level.
In this example, the Headquarters level uses USD, the G&A level uses GBP, and the Sales level uses CAD. The sheet, with levels down the rows, displays data in USD because it's the currency of the top-most level in this sheet.
The data you enter for any level on this sheet with levels in the rows is USD. When you change your view, and choose the G&A level, the sheet displays GBP again, converted from USD with the exchange rate chosen for the accounts.