I'm searching for a Citibank branch in Leipzig.
I've checked google maps and it's not really updated because the one that was mentioned in Goethestrasse was changed into a TargoBank.
The German retail banking arm of Citibank, which was sold to Crédit Mutuel in December 2008 and formally rebranded Targobank. So you cannot find any Citibank branch in Germany.
You can still find some Citibank adresses in Internet, but the information there is just obsolete and if you go there you will find a Targobank branch.
But as you already mentioned in comments, Targobank can perform actions for former Citibank customers.
If the one in Goethestrasse was acceptable (before it changed into a TargoBank), then it would seem that according to their website:
There is one in Lützowstrasse as well.