Those are likely to be explained here somewhere, but the workshop manual does a good job too.
here:
https://guzzitek.org/gb/ma_us_uk/1100/V11_1999-2003_Atelier(Compil-GB-D-NL).pdf
Section D, starting on page 57, covers regular maintence. Best to read all of that section, actually.
Engine oil page 60 ff., filter follows that.
Gearbox oil page 74 ff.
PS: the linked document is a compilation. The "section D" I referred to is in the first section, for the earlier models. However, the information doesn't turn up again in the later sections of the document, i.e. in the section for the later models, so I assume that the information for the first model continues to apply for all following models.