This is the 8676th most frequent Korean word.
가족들을
"Families" or "family members" (plural form).
Here, '가족들을' (gajokdeuruel) is used as the object of the verb '만나러' (manareo), indicating the family members who are to be met.
가족들을 만나러 고향에 갔어요.
I went to my hometown to meet my family.
In this sentence, '가족들을' is used as the object that signifies the recipients of the action '준비했어요' (prepared).
저는 가족들을 위해 저녁을 준비했어요.
I prepared dinner for my family.
Here, '가족들을' is employed to denote the people who are thought about in the mental action described by '생각하면' (when thinking).