BackboneJS – extracting url parameters inside a render() method

I have a page with an url that looks like so:

some.unit.gov/app/source/index.jsp#someActivityPage?10/NEW/20?true

window.location.host      //returns : 'some.unit.gov' 
window.location.pathname  // returns : '/app/source/index.jsp
window.location.search    // always return ' '

The host application consists other embedded links , which when clicked redirects the page
(which is the part after ‘#’).

Please note:
values ‘someActivityPage’, ‘NEW’, ‘true’ – are all dynamic values
Both numbers (10, 20) – are dynamic as well

How can I extract the ‘true’ value of the url in a render() method of BackboneJS.

The issue is :
In chrome dev tools

window.location.href.substr(window.location.href.lastIndexOf('?') + 1);  //returns 'true' exactly what I need

But inside the application, I suspect since javascript loads all the views on initial application load, always returns some.unit.gov/app/source/index.jsp because the view has already been initialized.

I also tried :

var searchParams = new URLSearchParams(window.location.search);
searchParams.has('false');

This always returns false regardless of what argument I provide.