Update, so filtering works properly.

Bulk update works as well

app/assets/javascripts/milestone_select.js.coffee

@@ -74,7 +74,10 @@ class @MilestoneSelect
           $selectbox.hide()
           $value.show()
         clicked: (e) ->
-          if $dropdown.hasClass "js-filter-submit"
+          if $dropdown.hasClass 'js-filter-bulk-update'
+            return
+            
+          if $dropdown.hasClass 'js-filter-submit'
             $dropdown.parents('form').submit()
           else
             selected = $selectbox

app/assets/javascripts/users_select.js.coffee

@@ -137,6 +137,8 @@ class @UsersSelect
           page = $('body').data 'page'
           isIssueIndex = page is 'projects:issues:index'
           isMRIndex = page is page is 'projects:merge_requests:index'
+          if $dropdown.hasClass('js-filter-bulk-update')
+            return
 
           if $dropdown.hasClass('js-filter-submit') and (isIssueIndex or isMRIndex)
             Issues.filterResults $dropdown.closest('form')

app/views/shared/issuable/_filter.html.haml

@@ -37,10 +37,10 @@
                 %li
                   %a{href: "#", data: {id: "close"}} Closed
           .filter-item.inline
-            = dropdown_tag("Assignee", options: { toggle_class: "js-user-search js-update-assignee js-filter-submit", title: "Assign to", filter: true, dropdown_class: "dropdown-menu-user dropdown-menu-selectable",
+            = dropdown_tag("Assignee", options: { toggle_class: "js-user-search js-update-assignee js-filter-submit js-filter-bulk-update", title: "Assign to", filter: true, dropdown_class: "dropdown-menu-user dropdown-menu-selectable",
               placeholder: "Search authors", data: { first_user: (current_user.username if current_user), null_user: true, current_user: true, project_id: @project.id, field_name: "update[assignee_id]" } })
           .filter-item.inline
-            = dropdown_tag("Milestone", options: { title: "Assign milestone", toggle_class: 'js-milestone-select js-extra-options js-filter-submit', filter: true, dropdown_class: "dropdown-menu-selectable dropdown-menu-milestone", placeholder: "Search milestones", data: { show_no: true, field_name: "update[milestone_id]", project_id: @project.id, milestones: namespace_project_milestones_path(@project.namespace, @project, :json), use_id: true } })
+            = dropdown_tag("Milestone", options: { title: "Assign milestone", toggle_class: 'js-milestone-select js-extra-options js-filter-submit js-filter-bulk-update', filter: true, dropdown_class: "dropdown-menu-selectable dropdown-menu-milestone", placeholder: "Search milestones", data: { show_no: true, field_name: "update[milestone_id]", project_id: @project.id, milestones: namespace_project_milestones_path(@project.namespace, @project, :json), use_id: true } })
           = hidden_field_tag 'update[issues_ids]', []
           = hidden_field_tag :state_event, params[:state_event]
           .filter-item.inline