Ruby on Rails: How to define a controller definition per shim?

First time asking something here on StackOverflow. So excited!

Basically, I'm wondering what the correct design pattern is for what I'm trying to accomplish. I have all my code working but was wondering it there's a more elegant, "RoR Way" to put it all together. For a language/framework so beautiful, it just feels like I've done this wrong:

I have a single master layout page ("WeekSummary") I'm using to display a bunch of "DaySummary" shims. All shims derive from the same template "_day_summary.html.erb."

On WeekSummary, I'm able to pass variables to individual shims fairly easily, eg:

<%= render 'layouts/day_summary', date: '2016-08-12' %>
<%= render 'layouts/day_summary', date: '2016-08-11' %>

But now I'm having trouble evoking a "day_summary" controller definition per each shim. Essentially, at this point in the render lifecycle, I believe I've already passed through the "C" part when the RoR engine called my "week_summary" definition (which I did hold some business logic). But now I want the RoR engine to go back to the controller and call a "day_summary" controller definition per each shim I've defined on WeekSummary view page. I would like all variables/definitions to be then locally scoped to each shim (so I can reuse the same var names, etc).

I wasn't able to figure out how to do that though so right now I've simply dumped all my shim-specific business logic at the top of the "_day_summary.html.erb" in a massive <% %> block. Having so much business logic there in a View shim seems wrong though.

I hope this made sense. Does anyone have any suggestions for how to properly do this? Essentially, I'm trying to encapsulate the rendering of each shim into its own MVC lifecycle/pattern, if that makes sense. Thank you!