How to output @model_name1.each do |model1| in model_name2.index?

Question

Design patterns

There is MVC model_name1 and model_name2.
Each has an index view.
You want to output <%= @model_name1.each do |model_name1| %> ... <% end %> at index model_name2.
How is it implemented?
In the model_name2 controller or in the model_name1 controller?
In what way is this implemented?
If anyone does this, please let me know.
Thanks in advance!