GroupsFinder should also returns groups of authorized projects

app/finders/groups_finder.rb

@@ -16,7 +16,10 @@ class GroupsFinder < UnionFinder
   def all_groups
     groups = []
 
-    groups << Group.member_self_and_descendants(current_user.id) if current_user
+    if current_user
+      groups << Group.member_self_and_descendants(current_user.id)
+      groups << Group.where(id: current_user.authorized_projects.select(:namespace_id))
+    end
     groups << Group.unscoped.public_to_user(current_user)
 
     groups

spec/finders/groups_finder_spec.rb

@@ -77,6 +77,15 @@ describe GroupsFinder do
               is_expected.to contain_exactly(public_subgroup, internal_subgroup, private_subgroup)
             end
           end
+
+          context 'authorized to private project' do
+            it 'returns the subgroup of the project' do
+              subproject = create(:empty_project, :private, namespace: private_subgroup)
+              subproject.add_guest(user)
+
+              is_expected.to include(private_subgroup)
+            end
+          end
         end
       end
     end