In Wordpress I have a page with the slug logged-user with a parent page ecadmin, making it accessible under the URL /ecadmin/logged-user/.
Since it has a parent page, I (or any other user) can create a page with the same slug logged-user as long as it isn't nested under the same parent page.
The problem now is that I cannot create a single page template page-logged-user.php in theme's folder, as this template can be potentially applied to any other page named logged user no matter where it belongs hierarchly.
Is there a way to name the template file in such way that is referencing to its parent page(s) as well? E.g. page-ecadmin-logged-user.php
The feature you are hoping for doesn't exist, but there is a quite simple way to accomplish what you want to do:
You can create a custom page template [whatever-you-want].php and place this comment in the header
/*
Template Name: Logged In User
*/
That template will be available in the Page Attributes meta box for any "Page" in Wordpress, but will only be applied to a given page if selected in that meta box.
Note:
All content creators have access to the page attributes meta box by default. If you are worried about users applying that template inappropriately you could hide the Page Attributes meta box from everyone who isn't an admin:
function remove_post_custom_fields() {
if (!current_user_can( 'create_users' )){
remove_meta_box( 'pageparentdiv' , 'post' , 'normal' );
}
}
add_action( 'admin_menu' , 'remove_post_custom_fields' );
http://www.wpbeginner.com/wp-themes/how-to-create-a-custom-page-in-wordpress/