Top N filters in Tableau - Dashboard Guide

Dashboard Mode - Top N filters

Dashboard Goal

Find the top N products by sales amount to focus on best sellers.

Sample Data

Product	Category	Sales
Notebook	Stationery	1200
Pen	Stationery	800
Desk Chair	Furniture	1500
Monitor	Electronics	2000
Mouse	Electronics	900
Stapler	Stationery	400
Table	Furniture	1100

Dashboard Components

• Parameter: Top N - User selects a number (e.g., 3) to show top N products.
• Calculated Field: Rank by Sales - Ranks products by sales descending.
  Formula: RANK_UNIQUE(SUM([Sales]), 'desc')
• Filter: Top N Filter - Filters products where Rank by Sales <= [Top N].
• Bar Chart: Shows products on X-axis and sales on Y-axis, filtered by Top N filter.
• Table: Lists Product, Category, and Sales for the filtered top N products.

Dashboard Layout

+----------------------+----------------------+
|      Top N Parameter  |      Bar Chart       |
|  (User input control) |  (Top N products)    |
+----------------------+----------------------+
|                      Table (Top N products)   |
+----------------------------------------------+

Interactivity

User changes the Top N parameter to select how many top products to display.

The Rank by Sales calculated field ranks all products by sales.

The Top N Filter uses the parameter to filter products with rank less than or equal to the selected number.

The bar chart and table update automatically to show only the top N products by sales.

Self Check

If you set the Top N parameter to 2, which products appear in the bar chart and table?

Answer: Monitor (2000 sales) and Desk Chair (1500 sales) appear because they have the highest sales.

Key Result

Dashboard shows top N products by sales with a parameter to select N, updating bar chart and table accordingly.

Practice

1. What is the main purpose of using a Top N filter in Tableau?

easy

A. To remove all null values from the dataset

B. To sort data alphabetically

C. To display only the highest ranked data points based on a measure

D. To change the color of the chart dynamically

Solution

1. Step 1: Understand the concept of Top N filter

   A Top N filter is used to show only the top items based on a ranking measure, such as sales or profit.

2. Step 2: Identify the purpose in Tableau

   It helps focus on the most important data points by filtering out lower-ranked items.

3. Final Answer:

   To display only the highest ranked data points based on a measure -> Option C

4. Quick Check:

   Top N filter = show top ranked data [OK]

Hint: Top N filters show only the best items by rank [OK]

Common Mistakes:

• Confusing Top N filter with sorting
• Thinking it removes nulls instead of filtering by rank
• Assuming it changes visual styles only

2. Which of the following is the correct way to create a Top N filter using a calculated field in Tableau?

easy

A. SUM([Sales]) > [Top N Parameter]

B. RANK(SUM([Sales])) <= [Top N Parameter]

C. IF [Sales] = MAX([Sales]) THEN 1 ELSE 0 END

D. INDEX() = [Top N Parameter]

Solution

1. Step 1: Understand the use of RANK() function

   The RANK() function assigns a rank number to each row based on a measure like SUM([Sales]).

2. Step 2: Apply the Top N filter condition

   Filtering with RANK(SUM([Sales])) <= [Top N Parameter] keeps only the top N ranked items.

3. Final Answer:

   RANK(SUM([Sales])) <= [Top N Parameter] -> Option B

4. Quick Check:

   Use RANK() with <= Top N [OK]

Hint: Use RANK() with <= parameter for Top N filter [OK]

Common Mistakes:

• Using SUM([Sales]) > parameter instead of rank comparison
• Confusing INDEX() with RANK() for Top N
• Using equality instead of less than or equal

3. Given the following Tableau calculated field for a Top N filter:

RANK(SUM([Profit])) <= 3

What will this filter do when applied to a sales dataset?

medium

A. Show the bottom 3 products by profit

B. Show all products with profit less than or equal to 3

C. Show products ranked exactly 3 by profit

D. Show the top 3 products by profit

Solution

1. Step 1: Analyze the RANK() function usage

   RANK(SUM([Profit])) ranks products from highest to lowest profit by default.

2. Step 2: Understand the filter condition <= 3

   This condition keeps products ranked 1, 2, or 3, meaning the top 3 products by profit.

3. Final Answer:

   Show the top 3 products by profit -> Option D

4. Quick Check:

   RANK() <= 3 means top 3 items [OK]

Hint: RANK() <= 3 always shows top 3 by measure [OK]

Common Mistakes:

• Thinking it shows bottom 3 instead of top 3
• Confusing rank number with measure value
• Assuming equality means only rank 3, not 1 to 3

4. You created a Top N filter with this calculated field:

RANK(SUM([Sales])) < [Top N Parameter]

But when you set the parameter to 5, it only shows 4 items. What is the issue?

medium

A. The filter should use <= instead of < to include the 5th item

B. The parameter value must be a string, not a number

C. RANK() function does not work with parameters

D. The filter should use > instead of <

Solution

1. Step 1: Understand the filter condition < [Top N Parameter]

   The condition RANK() < 5 includes ranks 1, 2, 3, and 4 but excludes rank 5.

2. Step 2: Correct the condition to include the 5th item

   Changing the condition to RANK() <= 5 will include the item ranked 5.

3. Final Answer:

   The filter should use <= instead of < to include the 5th item -> Option A

4. Quick Check:

   Use <= to include Top N items [OK]

Hint: Use <= to include the exact Top N rank [OK]

Common Mistakes:

• Using < excludes the Nth item
• Thinking parameter type causes issue
• Believing RANK() can't use parameters

5. You want to create a dynamic Top N filter in Tableau that lets users select the number of top products to display by sales. Which combination of features should you use?

hard

A. Create a parameter for N, a calculated field using RANK(SUM([Sales])) <= N, and apply it as a filter

B. Create a filter on SUM([Sales]) > N without using parameters

C. Use INDEX() = N in a calculated field and apply as a filter

D. Sort products by sales and manually select top N in the view

Solution

1. Step 1: Use a parameter to let users select N

   Parameters allow users to input or select a value dynamically, such as the number of top products.

2. Step 2: Create a calculated field with RANK(SUM([Sales])) <= N

   This calculated field ranks products by sales and filters to keep only the top N based on the parameter.

3. Step 3: Apply the calculated field as a filter on the view

   Applying this filter dynamically updates the view based on the parameter value.

4. Final Answer:

   Create a parameter for N, a calculated field using RANK(SUM([Sales])) <= N, and apply it as a filter -> Option A

5. Quick Check:

   Parameter + RANK() filter = dynamic Top N [OK]

Hint: Combine parameter with RANK() filter for dynamic Top N [OK]

Common Mistakes:

• Not using parameters for dynamic input
• Using INDEX() which depends on view order
• Manually selecting top N instead of filtering