I was wondering if anyone knows if there is a way to filter or sort odd and even files (reading the filename or ID) from the same folder.
No, I know of no way to separate even files from odd files. Using {filenamebase:-1} in a custom sort would get you sorting on the last digit, but they would be sorted in groups of 0, 1, 2, 3, 4, 5, 6, 7, 8, and 9. To go any further, mathematical operators would have to be used and our variables don't have any sort of scripting.
-Kirk