The fact that they can not be repaired would seem all the more reason to properly maintain don't you think?
The filter is inside the pan and obviously requires changing the fluid at the same time. This is not a trivial DIY job, take it to a dealer or do your homework before getting into it.
It would be a JATCO partAre there two filters in the CVT? One in the oil pan and one in the cooler?
Seems like this needs a full DIY writeup with part numbers for each filter and procedures to change the filters and refill the fluid.
If these filters are clogging up, it could be the cause of many CVT failures.