您可以创建自定义管线。在Rails指南中有许多不同的非资源路径可以查看。
其中一种方法是：

• 使用put，因为这是更新请求
• 使用on: :member捕获路由上的基站params[:id]

# routes.rb

resources :as do
  resources :bs do
    put 'increase_amount', on: :member
    put 'decrease_amount', on: :member
  end
end

# bs controller

def increase_amount()
   @b = B.find(params[:id])
   amount = @b.amount + params[:amount]
   if @b.update(amount: amount)
     ...
   else
     ...
   end
end

def decrease_amount()
   @b = B.find(params[:id])
   amount = @b.amount - params[:amount]
   if @b.update(amount: amount)
     ...
   else
     ...
   end
end

# haven't verified this is the correct route name, confirm using rake routes
<%= form_tag(increase_amount_a_bs_path(@a, @b), method: :put) do %>
  <%= label_tag(:amount, "Increase Amount:") %>
  <%= number_field_tag(:amount) %>
  <%= submit_tag("Update Amount") %>
<% end %>

<%= form_tag(decrease_amount_a_bs_path(@a, @b), method: :put) do %>
  <%= label_tag(:amount, "Decrease Amount:") %>
  <%= number_field_tag(:amount) %>
  <%= submit_tag("Update Amount") %>
<% end %>

至于弹出窗口，我不确定你的技术栈中有什么前端库，但Bootstrap是一个选项，模态