diff -ru redmine-2.5.1/app/models/issue.rb redmine/app/models/issue.rb
--- redmine-2.5.1/app/models/issue.rb	2014-03-29 17:56:36.000000000 +0100
+++ redmine/app/models/issue.rb	2014-06-23 13:12:05.046658189 +0200
@@ -117,6 +117,9 @@
         when 'own'
           user_ids = [user.id] + user.groups.map(&:id).compact
           "(#{table_name}.author_id = #{user.id} OR #{table_name}.assigned_to_id IN (#{user_ids.join(',')}))"
+        when 'group'
+          user_ids = ([user.id] + user.groups.map(&:id).compact + user.groups.map(&:users).flatten.map(&:id)).uniq
+          "(#{table_name}.author_id in (#{user_ids.join(',')}) OR #{table_name}.assigned_to_id IN (#{user_ids.join(',')}))"
         else
           '1=0'
         end
@@ -137,6 +140,8 @@
           !self.is_private? || (self.author == user || user.is_or_belongs_to?(assigned_to))
         when 'own'
           self.author == user || user.is_or_belongs_to?(assigned_to)
+        when 'group'
+          user.groups.map(&:users).flatten.uniq.inject(false) { |p, u| p ||= (self.author == u || u.is_or_belongs_to?(assigned_to)) }
         else
           false
         end
diff -ru redmine-2.5.1/app/models/role.rb redmine/app/models/role.rb
--- redmine-2.5.1/app/models/role.rb	2014-03-29 17:56:36.000000000 +0100
+++ redmine/app/models/role.rb	2014-06-20 09:43:24.768383152 +0200
@@ -36,7 +36,8 @@
   ISSUES_VISIBILITY_OPTIONS = [
     ['all', :label_issues_visibility_all],
     ['default', :label_issues_visibility_public],
-    ['own', :label_issues_visibility_own]
+    ['own', :label_issues_visibility_own],
+    ['group', :label_issues_visibility_group]
   ]
 
   scope :sorted, lambda { order("#{table_name}.builtin ASC, #{table_name}.position ASC") }
diff -ru redmine-2.5.1/config/locales/en.yml redmine/config/locales/en.yml
--- redmine-2.5.1/config/locales/en.yml	2014-03-29 17:56:39.000000000 +0100
+++ redmine/config/locales/en.yml	2014-06-23 13:00:57.057703829 +0200
@@ -875,6 +875,7 @@
   label_issues_visibility_all: All issues
   label_issues_visibility_public: All non private issues
   label_issues_visibility_own: Issues created by or assigned to the user
+  label_issues_visibility_group: Issues created by or assigned to the user's group(s)
   label_git_report_last_commit: Report last commit for files and directories
   label_parent_revision: Parent
   label_child_revision: Child
diff -ru redmine-2.5.1/config/locales/fr.yml redmine/config/locales/fr.yml
--- redmine-2.5.1/config/locales/fr.yml	2014-03-29 17:56:39.000000000 +0100
+++ redmine/config/locales/fr.yml	2014-06-23 13:02:20.152697782 +0200
@@ -855,6 +855,7 @@
   label_issues_visibility_all: Toutes les demandes
   label_issues_visibility_public: Toutes les demandes non privées
   label_issues_visibility_own: Demandes créées par ou assignées à l'utilisateur
+  label_issues_visibility_group: Demandes créées par ou assignées au(x) groupe(s) de l'utilisateur
   label_export_options: Options d'exportation %{export_format}
   label_copy_attachments: Copier les fichiers
   label_copy_subtasks: Copier les sous-tâches