How to add values to a bar graph in Report Editor?
Which version are you using?
There is a wizard that will walk you through creating a "Chart". Once a data source has been added you can specify which fields are used, assign labels, etc.
I suggest to review the Configuration guide for your version for details around creating and editing reports:
https://support.oneidentity.com/technical-documents/identity-manager/8.0.2/configuration-guide/96#TOPIC-1023241
Trevor