All of the previous AI Filters have a counterpart in the Effects menu. This allows for the Effects to be live and thus changable at any time. If you want to simulate the old Filter workflow, just apply the Effect and then Expand Appearance from the object menu.
If you have any third-party filters installed, like the Phantasm plug in or something, the Filter menu will still be there, but it's in a new location. Look for it under the Object menu.
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