Hi @anasustic !
Can you please confirm while opening page properties of a page, you are getting encoded URL (http://localhost:4506/mnt/overlay/wcm/core/content/sites/properties.html?item=%2Fcontent%2Fzkb%2Fde%2Fprivate%2Fdetail), as when I am trying to open page properties of any page it is coming like https://localhost:4502/mnt/overlay/wcm/core/content/sites/properties.html?item=/content/we-retail/us/en/experience/arctic-surfing-in-lofoten.
Also, I am able to hide a tab using below render condition properties,

param.item will get you /content/we-retail/us/en/experience/arctic-surfing-in-lofoten.
For debugging, you can use
<%@ page import="org.apache.commons.logging.Log" %>
<%@ page import="org.apache.commons.logging.LogFactory" %>
and logging statement as
Log logger = LogFactory.getLog( this.getClass( ) );
String suffix = slingRequest.getParameter("item");
logger.info( "This is a suffix" + suffix);
You can see the logs in error.log of aem instance.
Below is my /libs/granite/ui/components/coral/foundation/renderconditions/simple/simple.jsp
<%@ include file="/libs/granite/ui/global.jsp" %><%
%><%@ page session="false"
import="com.adobe.granite.ui.components.Config,
com.adobe.granite.ui.components.rendercondition.RenderCondition,
com.adobe.granite.ui.components.rendercondition.SimpleRenderCondition" %>
<%@ page import="org.apache.commons.logging.Log" %>
<%@ page import="org.apache.commons.logging.LogFactory" %>
<%--###
Simple
======
.. granite:servercomponent:: /libs/granite/ui/components/coral/foundation/renderconditions/simple
:rendercondition:
A condition that takes a simple boolean for the decision.
It has the following content structure:
.. gnd:gnd::
[granite:RenderConditionsSimple]
/**
* The expression to evaluate.
*/
- expression (BooleanEL) = true
###--%><%
Log logger = LogFactory.getLog( this.getClass( ) );
Config cfg = cmp.getConfig();
String suffix = slingRequest.getParameter("item");
logger.info( "This is a suffix" + suffix);
boolean vote = cmp.getExpressionHelper().getBoolean(cfg.get("expression", "true"));
request.setAttribute(RenderCondition.class.getName(), new SimpleRenderCondition(vote));
%>
Note : This functionality will not work for tab when we are trying to create a page due to issue I mentioned in last reply.