In Swedish there is no theoretical limit, but more than 4 is uncommon. To split words you will need a dictionary and stemming/compounding rules for Swedish and process the word from left to right. Note also that in rare cases there can be multiple legal ways to split a given compound word.

As far as I can tell it is the same for German other than that they have a slightly different set of compounding rules, e.g. hyphen can be used in more cases in German.