Rails uses a list of prefixes to resolve templates and partials. While you can explicitly specify a prefix ("question/answer"), as suggested in another answer, this approach will fail if the template itself includes unqualified references to other partials.
Assuming that you have an ApplicationController superclass, and QuestionController inherits from it, then the places Rails would look for templates are, in order, "app/views/question/" and "app/views/application/". (Actually it will also look in a series of view paths, too, but I'm glossing over that for simplicity's sake.)
Given the following:
class QuestionController < ApplicationController
end
class AnotherQuestionController < ApplicationController
end
QuestionController._prefixes
# => ["question", "application"]
AnotherQuestionController._prefixes
# => ["another_question", "application"]
Solution #1. Place the partial under "app/views/application/" instead of "app/views/question/", where it will be available to both controllers.
Solution #2. Inherit from QuestionController, if appropriate.
class AnotherQuestionController < QuestionController
end
=> nil
AnotherQuestionController._prefixes
# => ["another_question", "question", "application"]
Solution #3. Define the class method AnotherQuestionController::local_prefixes
This was added in Rails 4.2.
class AnotherQuestionController < ApplicationController
def self.local_prefixes
super + ['question']
end
end
AnotherQuestionController._prefixes
# => ["another_question", "question", "application"]