Not Nanjing
Correct (it was guessed twice on the last page so I didn't think it would be so hard).Chengdu, Tianfu Financial Center.
(don't ask, how much research this was ... )
There's a lot of truth and hints in this!The combination of various European flags and stars makes me think that it's something to do with the EU as an institution. It's not one of the main buildings in Brussels or Strasbourg (and the numberplates aren't Dutch so not in NL), but could be one of the bits of admin that has been outsourced to member countries?
But the (then-)EC only adopted the star flag of the Council of Europe in the mid-1980s, stars weren't really a thing before then so unless it's something directly connected to the Council of Europe then I guess it post-dates the mid-80s? But architecturally it dates to before plate glass becoming a thing around the millennium-ish? So 1990s expansion time?