Filters were a function with the BIS environment. With BB10, BIS is no longer in play, so none of the functions that it had are directly available. Rather, it's now ActiveSync directly between the device and the email server. So, you'd likely need to do something on your email server to deal with this...perhaps a rule there that moves calendar invites to a different folder, and thereby keeps it off of the BB (or, if it arrived to the BB, removes it upon the next reconciliation).
Occam's Razor nearly always applies when troubleshooting technology issues!
If anyone has been helpful to you, please show your appreciation by clicking the button inside of their post. Please click here and read, along with the threads to which it links, for helpful information to guide you as you proceed. I always recommend that you treat your BlackBerry like any other computing device, including using a regular backup schedule...click here for an article with instructions.