Complex sentence: Underwood travelled to New Zealand, Singapore, Taiwan and the UK, promoting with Bardot but in early 2001 decided to leave the group in pursuit of a role in the production of "Hair".
Split into simpler sentences: Underwood travelled to New Zealand, Singapore, Taiwan and the UK, promoting with Bardot. In early 2001 she decided to leave the group in pursuit of a role in the production of "Hair".