app/controllers/admin/instances_controller.rb

@@ -38,7 +38,7 @@ module Admin
     end
 
     def filter_params
-      params.permit(:limited)
+      params.permit(:limited, :by_domain)
     end
   end
 end

app/helpers/admin/filter_helper.rb

@@ -6,7 +6,7 @@ module Admin::FilterHelper
   INVITE_FILTER        = %i(available expired).freeze
   CUSTOM_EMOJI_FILTERS = %i(local remote by_domain shortcode).freeze
   TAGS_FILTERS         = %i(hidden).freeze
-  INSTANCES_FILTERS    = %i(limited).freeze
+  INSTANCES_FILTERS    = %i(limited by_domain).freeze
 
   FILTERS = ACCOUNT_FILTERS + REPORT_FILTERS + INVITE_FILTER + CUSTOM_EMOJI_FILTERS + TAGS_FILTERS + INSTANCES_FILTERS
 

app/models/domain_block.rb

@@ -24,6 +24,8 @@ class DomainBlock < ApplicationRecord
   has_many :accounts, foreign_key: :domain, primary_key: :domain
   delegate :count, to: :accounts, prefix: true
 
+  scope :matches_domain, ->(value) { where(arel_table[:domain].matches("%#{value}%")) }
+
   def self.blocked?(domain)
     where(domain: domain, severity: :suspend).exists?
   end

app/models/instance_filter.rb

@@ -9,9 +9,13 @@ class InstanceFilter
 
   def results
     if params[:limited].present?
-      DomainBlock.order(id: :desc)
+      scope = DomainBlock
+      scope = scope.matches_domain(params[:by_domain]) if params[:by_domain].present?
+      scope.order(id: :desc)
     else
-      Account.remote.by_domain_accounts
+      scope = Account.remote
+      scope = scope.matches_domain(params[:by_domain]) if params[:by_domain].present?
+      scope.by_domain_accounts
     end
   end
 end

app/views/admin/instances/index.html.haml

@@ -11,6 +11,20 @@
   %div{ style: 'flex: 1 1 auto; text-align: right' }
     = link_to t('admin.domain_blocks.add_new'), new_admin_domain_block_path, class: 'button'
 
+= form_tag admin_instances_url, method: 'GET', class: 'simple_form' do
+  .fields-group
+    - Admin::FilterHelper::INSTANCES_FILTERS.each do |key|
+      - if params[key].present?
+        = hidden_field_tag key, params[key]
+
+    - %i(by_domain).each do |key|
+      .input.string.optional
+        = text_field_tag key, params[key], class: 'string optional', placeholder: I18n.t("admin.instances.#{key}")
+
+    .actions
+      %button= t('admin.accounts.search')
+      = link_to t('admin.accounts.reset'), admin_custom_emojis_path, class: 'button negative'
+
 %hr.spacer/
 
 - @instances.each do |instance|

config/locales/en.yml

@@ -302,6 +302,7 @@ en:
       back_to_account: Back To Account
       title: "%{acct}'s Followers"
     instances:
+      by_domain: Domain
       delivery_available: Delivery is available
       known_accounts:
         one: "%{count} known account"