If you know the original sorting parameters, then just do Data > Sort, and
set them up...............if you don't, then just quit the file without
saving and reopen and things will be as they were before you filtered.........

Vaya con Dios,
Chuck, CABGx3

This may not help this time, but you could add another column with just sequence
numbers in that column.

1, 2, 3,....

Then sort by whatever you want.  Then when you want to return to the original
sort order, you can sort by this helper column.