Fix PA for projects in nested groups

This change fixes the error on the group-level productivity
analytics feature when projects from sub-groups are selected.

Changelog: fixed
EE: true

ee/app/controllers/groups/analytics/application_controller.rb

@@ -29,7 +29,7 @@ class Groups::Analytics::ApplicationController < ApplicationController
   def load_project
     return unless @group && params['project_id']
 
-    @project = find_routable!(@group.projects, params['project_id'], request.fullpath)
+    @project = find_routable!(@group.all_projects, params['project_id'], request.fullpath)
   end
 
   private_class_method :increment_usage_counter

ee/spec/controllers/groups/analytics/productivity_analytics_controller_spec.rb

@@ -154,7 +154,7 @@ RSpec.describe Groups::Analytics::ProductivityAnalyticsController do
       end
 
       context 'for list of MRs' do
-        let!(:merge_request ) { create :merge_request, :merged}
+        let!(:merge_request ) { create :merge_request, :merged }
 
         let(:serializer_mock) { instance_double('BaseSerializer') }
 
@@ -182,6 +182,23 @@ RSpec.describe Groups::Analytics::ProductivityAnalyticsController do
           expect(response.headers['X-Total']).to eq '1'
           expect(response.headers['X-Total-Pages']).to eq '1'
         end
+
+        context 'when project from a sub-group is requested' do
+          let(:subgroup) { create(:group, parent: group) }
+          let(:project) { create(:project, group: subgroup) }
+
+          let(:params) { { group_id: group, project_id: project.full_path } }
+
+          before do
+            group.add_owner(current_user)
+          end
+
+          it 'succeeds' do
+            subject
+
+            expect(response).to have_gitlab_http_status(:ok)
+          end
+        end
       end
 
       context 'for scatterplot charts' do