You can access the current URL parameters via this.param
and it returns a PHP array.
Accessing page parameters
This example demonstrates how to access the tab
URL parameter in a page.
url = "/account/:tab" == {% if this.param.tab == 'details' %}Here are all your details
{% elseif this.param.tab == 'history' %}You are viewing a blast from the past
{% endif %}
If the parameter name is also a variable, then array syntax can be used.
url = "/account/:post_id" == {% set name = 'post_id' %}The post ID is: {{ this.param[name] }}
reference: https://octobercms.com/docs/markup/this-param