You can set a Watchdog rule to emit a log entry when any process goes over a CPU % threshold. Open the Watchdog via 'Options / Control / Process Watchdog (advanced rules)', then create a rule like shown below.
When creating a rule that matches all processes, you may receive a warning when as rule is added. Disregard that.
Alternatively, you can use the Sampling capability in 'Options / Log / Configure Sampling...'. However, the emitted CSV will require further digestion to retrieve interesting data.