To get a better idea of what multifunctionality is, you can read through some descriptions of multifunctional items.
Multifunctional affixes that and appear in different categories
Slovenian suffix -ic
See here and pages 29-44 here.
Slovenian suffix -in
See here.
Slovenian sufix -av
We have considered -av here and here.
Maximally multifunctional affixes that appear in both derivation and inflection
Slovenian sufix -ov
We have considered -ov in many of our works, which means that you can read more about it here, here and here. And for more on -ov BCMS, read this and this.
Slovenian sufix -l
We can observe -l in (past) participle and as a part of deverbal nouns and adjectives. To get more information about it, read this and this.
Sufix -j
We addressed the many functions of -j in several of our works, see for example here, here (pages 221–231), here, here.