Hey,
I noticed that you called the filterTable function here:
Instead, you should create an onChange event (clicking the plus sign) and call the function from inside the onChange event function (as explained above, at the third step).
As a general note, I recommend giving meaningful names to the elements instead of leaving the default names so that it’ll be easier for you to understand the code and fix bugs when there is a need.
I duplicated the page (" Copy of כל המשרות ") and corrected it so it works now. I saved the changes and haven’t published it. Please go through the code and let me know if anything is unclear.
Best,
Tal.