The custom data views in Tableau are views that a user can customize according to their analysis needs.
A custom data view is made from a normal data view by making some modifications in it or adding advanced functionalities and features in it.
In other words, custom views are views that represent a set of data in different ways.
Custom data views are alternate views of the same underlying data which presents a different story in every new view.
We can create custom views by making a drill-down dimension with predefined hierarchies.
In this case, every time you drill-down the next level, you will find data at a different level of granularity.
Another way of creating a custom view is by simply swapping the position of fields or dimensions in the Columns or Rows sections.
By swapping the position of dimensions, we can view our data in a new way.