Step 1). Create the Vendor/Module/etc/frontend/event.xml in your module
<event name="controller_action_postdispatch"> <observer name="change_title_filter" instance="VendorModuleObserverFiltertitle" /> </event>
Step 2). Create the Vendor/Module/Observer/Filtertitle.php in your module
<?php namespace VendorModuleObserver; use MagentoFrameworkEventObserverInterface; use MagentoFrameworkEventObserver; use MagentoFrameworkViewLayoutInterface; class Filtertitle implements ObserverInterface { protected $context; public function __construct( MagentoFrameworkViewElementTemplate $context, MagentoFrameworkViewResultPage $resultPage, MagentoFrameworkViewPageConfig $pageConfig ) { $this->pageConfig = $pageConfig; $this->resultPageFactory = $resultPage; $this->context = $context; } public function execute(MagentoFrameworkEventObserver $observer) { $layout = $this->context->getLayout(); $pageMainTitle = $layout->getBlock('page.main.title'); if ($pageMainTitle) { $blockfilter = $layout->getBlock('catalog.navigation.state'); if($blockfilter){ $selectedFilters = $blockfilter->getActiveFilters(); if (!empty($selectedFilters)){ $filters = array(); foreach($selectedFilters as $filter){ $filters[] = $blockfilter->stripTags($filter->getLabel()); } if(count($filters) > 0){ $activefilters = __("Your selection: ").implode(" - ", $filters); $pageMainTitle->setPageTitle($activefilters); } } } } } }