African city, a centrepiece for semiurban guidebook (6)

I believe the answer is:

bangui

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'african city' is the definition.
(capital of Central African Republic)

'a centrepiece for semiurban guidebook' is the wordplay.
'BANGUI' is hidden in amongst the letters.
But, I'm not sure how the hidden word is indicated.

Can you help me to learn more?

(Another definition for bangui that I've seen is " African city".)

I've seen this clue in The Times.

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