Yes, I do. On a daily basis, working for my clients abroad (lots of them are attorneys-at-law in their countries). Further I regularily communicate and judge as an arbitrator at the Court of Arbitration for Sport (CAS).
Necessary knowledge involves a good understanding for comparative law (I have worked for years at such an university institute) and the concepts behind what is not only the quite special legal language but different laws and legal systems.
Please do not hesitate to contact me in case of any queries.