Translation:They return to their home, that is, to Jakarta.
'They return to their home' should be fine here as well, it's just a more literal translation
The ending is important as it qualifies the sentence ... especially as Indonesians will often return their family home (most often this means their village) as opposed to their place of residence.
The problem is the ambiguity of this sentence. Rumah(nya) would refers to either 'their own respective home' or 'the home of someone (one of them/someone else/or any third person).'
Alice and Bob are staying at Charlie's home. THEY go out for the day, and then THEY return to HIS home.
An English speaker would never sat this. It would be: "They return to their home that is in Jakarta." Not "to Jakarta".
Well you might say "that is, in/at/to Jakarta" to clarify you actually mean their home in Jakarta, as opposed to their local hotel room or some local home or guest house or whatever. I have to say though that I'm growing weary of twisting Indonesian grammar into English grammar, as I really don't see how that helps me learn to hear and understand Indonesian the way it is actually spoken?