Well LCM between versions is not officially supported by Oracle.
You could manually export the map to a text file and import that text file to the new environment.
For an earlier project I tried through LCM only. It worked but I had to import all other artifacts first and then mapping separately.
As mentioned LCM is not "supported by Oracle' between version.
Certainly it may work however if you run into any issues Oracle will not support you on it as it is not a supported process.
Your can review supported paths below:
As already mentioned you can simply export a file from your source and import that text file to your target. Did you test that process and are saying it is not working?