• Open chrome://extensions/
• Load unpacked extension
• Open Employeer portal page
• Open devtools and select the panel BDTracker Calendar View
• Click on the filter search
• Wait calendar to be rendered

(to have the list back on view, just close the devtools and reload the page)

References:

• https://github.com/GoogleChrome/chrome-extensions-samples
• https://betterprogramming.pub/chrome-extension-intercepting-and-reading-the-body-of-http-requests-dd9ebdf2348b
• https://fullcalendar.io/