To create a report showing salary progression over the last 3 years by employee, utilizing the Employee Compensation Event object, you can use the standard "Compensation Changes Report." This report can be edited to include relevant Business Objects and fields, such as "Salary Plans Changed" and details of plan assignments, including assignment dates. The report can be based on data sources like "All Employee Compensation Events," and filters should be applied to look at event effective dates within the last 3 years to capture the progression.
Alternatively, the "Next Step Employee Compensation Step Progression" report can be used to view employee salary progression. This report lists employees who have had a compensation step change within a specified time period, capturing automatic, hired, and manual step changes. It allows drilling into details and can be accessed through search or the Compensation menu.
To view employee salary progression over the last 3 years by employee, you can use the Next Step Employee Compensation Step Progression report. 
This report:
To create a report showing salary progression over the last 3 years by employee using the Employee Compensation Event object:
