While she was in Japan, she frequently visited Kyoto.
Literal
She [topic-は] Japan [in-に] was [during-間に], [frequently-たびたび] Kyoto [object-を] visited.
~間に ('during the time when ~') marks the interval within which something happened. Different from ~間 alone, which highlights duration without bounding the inner event. たびたび is a reduplicated adverb for repeated occurrence — 'frequently, often.'