This is the 2430th most frequent Turkish word.
ilişkilerine
"To their relationships" or "to their connections."
In this sentence, 'ilişkilerine' is a dative plural form of 'ilişki' (relationship), referring to the relationships belonging to 'arkadaşlarının' (his friends).
Arkadaşlarının ilişkilerine her zaman saygı duyar.
He always respects his friends' relationships.
Here, 'ilişkilerine' is used to describe the dative plural relationships concerning 'kardeşinin arkadaşlık' (his sibling's friendships).
Kardeşinin arkadaşlık ilişkilerine karışmaktan çekinir.
He hesitates to interfere in his sibling's friendships.
In this instance, 'ilişkilerine' indicates dative plural relationships relevant to 'iş arkadaşlarının' (his colleagues).