This is the 180th most frequent Croatian word.
kojim
The Croatian word "kojim" means "which" or "whom" in English, typically used in the instrumental case.
Here, 'kojim' is used as a relative pronoun in instrumental case to refer to the path as an object of the action 'idem'.
Put kojim idem vodi do plaže.
The path I'm taking leads to the beach.
In this example, 'kojim' is used in the instrumental case to complement the verb phrase 'se moramo pozabaviti', specifying the means or manner.
To je problem kojim se moramo pozabaviti.
That is a problem we need to address.
'Kojima' here is in the instrumental case, plural, used after the preposition 's' and modifies the noun 'prijateljima' to indicate association.