In the long term it is difficult to see for an easy replacement for the city of London where Russian business is concerned.
In this case "to see for" (although, like the commenters above said, is grammatically incorrect) can mean imagine.
They're saying that they can't imagine a long term replace for London where Russian business is concerned.
Now "where Russian business is concerned" means that the entire sentence is talking about Russian business. So the previous statement refers to Russian business.
Another way to say this sentence is:
"It is difficult to see a long term Russian business replacement for the city of London"