MVC N Tier Seperation [on hold]

I understand that MVC Seperation and Architechture questions have been asked and covered on numerous occasions but having read through many of them, I can't find anything that fits to my questions.

Bit of background I originally (badly) designed the architecture of my project with the model, along with functions into 1 local Nuget package. I thought this may be a good idea to use going forward with other projects that will talk to the same database.

Having now read through other materials I realise that this was not the best option as many functions were included which is only specific to the original project. I have now started to strip this back and create a separated architecture with the following design:

Database, Models, Data Access (Repositories) ...... UI

Now to my question, with this design (please advise if I am not getting the correct concept) would I presume that each project pointing to the database would have it's own Service Layer / Business Layer, or would this reside in the controllers of the project itself?

Look forward to your replies.

Thanks,