Sorting Specific Fields
You can sort a specific field using the Sort dialog box.
- Open the Sort dialog box.Right-click (control-click on Mac) on the field that you want to sort and select Sort from the context menu.
- Specify the sorting options.Complete the Sort dialog box by specifying the following criteria:
- Sort order - Displays the sort results in ascending or descending order.
- Sort by – Sort by one of these three options:
- Data source order - the order that the data source naturally orders the data. Generally for relational data sources, this tends to be in alphabetical order. If you are using a cube, this order is the defined hierarchal order of the members within a dimension.
- Alphabetic - the order of the letters in the alphabet.
- Field - order the data based on the associated values of another field. For example, you could order several products by their total sales values.When working with a relational data source and sorting by another field, you must also specify the aggregation function to use. This option is not available for multidimensional data sources because aggregations are defined when the cube is created and cannot be modified in Tableau. In Tableau, multidimensional data sources are supported only in Windows.
A typical scenario is to sort one or more dimensions by a measure. For example, the Sort dialog box shown below is configured to sort the members of the Customer Segment field in descending order and by the sum of the Sales measure. The results will be displayed so that the member with the highest sales is displayed first, the member with the second highest sales is displayed second, and so on.You should keep the following rules in mind when interpreting the sort results:
- Tableau computes the sort across the entire table using the specified criteria. Refer to Example – Sorting a Text Table for an example.
- Sorts do not break the dimension hierarchy. Sorted fields are always displayed within the ordered context already set forth by the fields on the Rows and Columns shelves. This means that Tableau will not rearrange any of the headers of the fields that appear before (to the left of) the sorted field.If you want to break the dimension hierarchy when sorting a multidimensional data source, place only the hierarchy level that you want sorted on the Rows or Columns shelf.
Please read these articlesUnderstanding Sorting in Tableau - The Information Lab
thank you for Quick reply