Belgium updates building in the capital (8)
I believe the answer is:
budapest
'capital' is the definition.
(Budapest is an example)
'belgium updates building' is the wordplay.
'belgium' becomes 'b' (international vehicle registration code).
'building' indicates an anagram.
'updates' anagrammed gives 'udapest'.
'b'+'udapest'='BUDAPEST'
'in the' acts as a link.
(Other definitions for budapest that I've seen before include "city of Europe" , "Put beads in the European city" , "capital location" , "Capital of Hungary" , "Hungary's capital" .)