How to show the top 5 and bottom 5 sales in Tableau?

The clean approach is two sets combined into one.

Create a set on the dimension with a Top condition — top 5 by `SUM(Sales)` — and a second with a Bottom condition on the same measure. Then select both in the Data pane, right-click and choose Create Combined Set, taking all members of both.

Put the combined set on Rows and the measure on Columns, and you get a single view of ten bars. Because the sets are dynamic, membership updates as the data changes.

A parameter for N makes it adjustable — reference it in each set's condition, and one control drives both.

The alternative is a table calculation using `INDEX()` or `RANK()`, filtered to the first and last N. It works, but the filter applies after the calculation, so the interaction with other filters needs more care than the set approach.