title: Tableau: How do I create categories from a dimension based on the count of another dimension?
body: <p>I have a spreadsheet of flight delay data, and I'm working on a worksheet that shows the total delay time per airport. I want to filter the dimension "Airports", i.e. create categories of airports, "Small", "Medium" and "Large", based on the number of departures from each airport, which is calculated by counting the Dimension "Flight Number".</p>
  
  <p>I currently have a IN/OUT filter using a set "Small Airports", created on the dimension "Airports" based on the condition </p>
  
  <p>COUNT([Flight Number])&lt;500,</p>
  
  <p>but this method only lets me divide the airports into two categories.</p>
  
  <p>EDIT: @Siva Here's a sample of the columns I'm referring to, it's copied into an Excel sheet as the sheet I'm actually using in Tableau has over 30 columns;<a href="https://i.stack.imgur.com/U7snO.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/U7snO.png" alt="extract from the database into an Excel sheet"></a></p>