A role can be denied access to a contiguous subset of levels in a hierarchy by specifying the Top Level and Bottom Level settings. Lowering the Top Level setting prevents users with that role from seeing the topmost aggregates.
If you change All to another choice using the Top Level menu, the BI client user might not be able to see important information in the BI client application such as Grand Totals.
Raising the Bottom Level setting restricts how far an Teradata OLAP Connector user with that role can drill down. Use this setting to prevent BI client application users from seeing individual fact table entries.
Teradata Schema Workbench defines how to compute aggregate values for levels by using the Aggregation Policy. See Aggregation Policy.