To compare the budget for 4 years, use the report template,
P&L with Projected Total (Multi-Period) and set the criteria as:
Report month in the orange banner to the period you wish to start from
Period type as Yearly
Start period as Start This Financial Year
End Period as Number of periods and 4 years
The Start and End Month/Year will be displayed as information
You can of course choose other periods as may be required using the same method.