A set splits the members of a dimension into two: In the set and Out of it. Right-click a dimension and choose Create > Set.... The dialog looks like the filter dialog:
- General: tick members by hand. The set is a fixed list.
- Condition: a rule, such as SUM(Profit) < 0.
- Top: the top or bottom N by a measure, such as the top 20 customers by Sales.
Condition and Top sets update when the data changes. On a shelf a set shows In and Out, so it can color, split or filter a view. In a calculated field it's true or false: IF [Top Customers] THEN "Top 20" ELSE "Everyone else" END.
Two sets on the same dimension can be combined: right-click one > Create Combined Set... and keep all members, only shared members, or members of the first set that aren't in the second.
Groups merge members into new names; sets only mark them In or Out.