Along with the Expenses app, we’ve also released a an update for the Approvals app to support customization of different approval types. With this update, partners can choose which fields and charts to expose for different approval types.
The original version of the app shipped with immersive experiences for approving Expenses and Timesheets. This update enables creating similar experiences for any workflow approval type. It also enables customizing the Expense and Timesheets experiences.
This feature is explained in detail in the following whitepaper (https://mbs.microsoft.com/partnersource/northamerica/deployment/documentation/msdaxcustomizedataapprowin).