3 files changed, 41 insertions, 2 deletions
diff --git a/app/controllers/clusters/clusters_controller.rb b/app/controllers/clusters/clusters_controller.rb
index 2e9c77ae55c..a6d40062c46 100644
--- a/app/controllers/clusters/clusters_controller.rb
+++ b/app/controllers/clusters/clusters_controller.rb
@@ -18,8 +18,8 @@ class Clusters::ClustersController < Clusters::BaseController
   STATUS_POLLING_INTERVAL = 10_000
 
   def index
-    clusters = ClustersFinder.new(clusterable, current_user, :all).execute
-    @clusters = clusters.page(params[:page]).per(20)
+    clusters = ClusterAncestorsFinder.new(clusterable.subject, current_user).execute
+    @clusters = Kaminari.paginate_array(clusters).page(params[:page]).per(20)
   end
 
   def new
diff --git a/app/finders/cluster_ancestors_finder.rb b/app/finders/cluster_ancestors_finder.rb
new file mode 100644
index 00000000000..0d23599459f
--- /dev/null
+++ b/app/finders/cluster_ancestors_finder.rb
@@ -0,0 +1,31 @@
+# frozen_string_literal: true
+
+class ClusterAncestorsFinder
+  def initialize(clusterable, user)
+    @clusterable = clusterable
+    @user = user
+  end
+
+  def execute
+    clusterable.clusters + ancestor_clusters
+  end
+
+  private
+
+  attr_reader :clusterable, :user
+
+  def ancestor_clusters
+    Gitlab::GroupHierarchy.new(base_query).base_and_ancestors.flat_map do |group|
+      group.clusters
+    end
+  end
+
+  def base_query
+    case clusterable
+    when Project
+      Group.joins(:projects).where(projects: { id: clusterable.id })
+    when Group
+      Group.where(id: clusterable.parent_id)
+    end
+  end
+end
diff --git a/spec/finders/cluster_ancestors_finder_spec.rb b/spec/finders/cluster_ancestors_finder_spec.rb
new file mode 100644
index 00000000000..d421fe23c27
--- /dev/null
+++ b/spec/finders/cluster_ancestors_finder_spec.rb
@@ -0,0 +1,8 @@
+# frozen_string_literal: true
+
+require 'spec_helper'
+
+describe ClusterAncestorsFinder do
+  let(:group) { create(:group) }
+  let(:project) { create(:project, group: group) }
+end