Issue confirmed.

@C-Lodder
@laoneo

This issue is really bothering as we can't test Menus/Menu items/associations in order to solve other bugs.

Basically, as far as I could see: the global searchtools layout default.php $selectorFieldname accepts only one field and not an array which prevents displaying 2 separate fields in the bar.

The menus and associations layout searchtools overrides are old code which anyway have to be totally modified or deleted for these 2 components.

Once deleted for com_menus, we can easily solve the Menus Manager by changing code in
/administrator/components/com_menus/tmpl/menus/default.php line 43 to
<?php echo JLayoutHelper::render('joomla.searchtools.default', array('view' => $this, 'options' => array('selectorFieldName' => 'client_id'))); ?>

But although we can do the same for Menu Items, we will not get the menutype filter as there is no way in code to add it to the client_id

Will take a look tonight hopefully

@C-Lodder
While you are at it and as we have now noresults, please modify the tpl for menus/ menus items and modal.
I.e. we should have

				<?php if (!empty($this->items)) : ?>
					<table class="table table-striped" id="itemList">

and NOT

			<?php if (empty($this->items)) : ?>
					<joomla-alert type="warning"><?php echo JText::_('COM_LANGUAGES_MULTILANGSTATUS_NONE'); ?></joomla-alert>
				<?php else : ?>
					<table class="table table-striped" id="itemList">

which anyway makes no sense at all....

@infograf768 so remove the alert? I thought alerts were always displayed in Joomla when no results were found...

the alert is obtained by

<field
			name="search"
			type="text"
			hint="JSEARCH_FILTER"
			noresults="JGLOBAL_NO_MATCHING_RESULTS"
		/>

new in 4.0

/Applications/MAMP/htdocs/installmulti/joomla40/administrator/components/com_cache/forms/filter_cache.xml:19: noresults="JGLOBAL_NO_MATCHING_RESULTS"
/Applications/MAMP/htdocs/installmulti/joomla40/administrator/components/com_checkin/forms/filter_checkin.xml:10: noresults="COM_CHECKIN_NO_ITEMS"
/Applications/MAMP/htdocs/installmulti/joomla40/administrator/components/com_languages/forms/filter_installed.xml:19: noresults="JGLOBAL_NO_MATCHING_RESULTS"
/Applications/MAMP/htdocs/installmulti/joomla40/administrator/components/com_menus/forms/filter_items.xml:29: noresults="JGLOBAL_NO_MATCHING_RESULTS"
/Applications/MAMP/htdocs/installmulti/joomla40/administrator/components/com_menus/forms/filter_itemsadmin.xml:32: noresults="JGLOBAL_NO_MATCHING_RESULTS"
/Applications/MAMP/htdocs/installmulti/joomla40/administrator/components/com_modules/forms/filter_modules.xml:20: noresults="COM_MODULES_MSG_MANAGE_NO_MODULES"
/Applications/MAMP/htdocs/installmulti/joomla40/administrator/components/com_modules/forms/filter_modulesadmin.xml:23: noresults="COM_MODULES_MSG_MANAGE_NO_MODULES"
/Applications/MAMP/htdocs/installmulti/joomla40/administrator/components/com_templates/forms/filter_styles.xml:19: noresults="COM_TEMPLATES_MSG_MANAGE_NO_STYLES"
/Applications/MAMP/htdocs/installmulti/joomla40/administrator/components/com_templates/forms/filter_templates.xml:19: noresults="COM_TEMPLATES_MSG_MANAGE_NO_TEMPLATES"
/Applications/MAMP/htdocs/installmulti/joomla40/components/com_modules/forms/filter_modules.xml:12: noresults="COM_MODULES_MSG_MANAGE_NO_MODULES"

Which means it is not implemented all over J, for example in com_contents where we have the old style alert.

a mess... what can I say...

PR: #19044

@infograf768 - please could you open a new issue for the noresults attribute you mentioned

Set to "closed" on behalf of @franz-wohlkoenig by The JTracker Application at issues.joomla.org/joomla-cms/18815

closed as having Pull Request #19044

@infograf768 - please could you open a new issue for the noresults attribute you mentioned

I will. Thanks.