It will generally be that the client base is more local. So you’ll be less likely working with financial institutions based in the city, but depending on the city, will be working with more clients in areas like Aerospace (Bristol), Media (Manchester), or car/vehicle manufacturing (Birmingham).
It’s not to say you won’t do financial services work as there are financial companies in all those cities, there will just be less of it than in the City of London. And sometimes your work will extend/cross over into to the City of London anyway.
To find out more about a firm’s work in a particular office you could look at regional Chambers profiles like this one:
https://chambers.com/legal-rankings/litigation-south-west-1:717:17149:1.
In addition, you could go on the firm’s website and search for partners in that office location and then look at their profile and see the type of clients they have worked for, like this one:
https://www.eversheds-sutherland.com/en/united-kingdom/people/bridgford-tom