Well, a couple things jump out…
Screen elements, such as the Slider elements, can only be accessed within a page event handler, such as the page’s onReady() function, or element event handlers, such as onChange(), onClick(), and others. Lines 366/7 and won’t work where you currently have them.
Perhaps, the variables lastFilterEmpMin and lastFilterEmpMax should be initialized inside of the page’s onReady() function.
You don’t have either slider onChange() event handler connected to its Slider. As you can see in the screenshot, the field for the onChange() event handler is blank:
See I want to respond to button clicks and page events for more details.
There might be other issues as well, but the above issues I saw immediately and caused the sliders to malfunction.