REVEN does not provide such a functionality out of the box for now.
Still, you can build your own trace comparison using the Analysis API. It requires:
- finding the region of interest (symbol, process, etc),
- parsing both traces with the Python API and outputting instructions, values, that you deem necessary into separate files,
- creating a comparison of those output files.
See https://blog.tetrane.com/2019/11/12/pe-parser-crash.html for an example of such a script.
You may also want to compare taint outputs, since those are accessible through the API as well.