Steps to reproduce the issue

• Login to Joomla 4 alpha backend
• Keep chrome console open
• Visit articles list /administrator/index.php?option=com_content

Expected result

Articles list should not have any JS error on page load

Actual result

JS error seen in console

searchtools.js?8d3a6407fa3397a32f1d85c1133aea51:188 
Uncaught TypeError: Cannot read property 'value' of null
    at Searchtools.checkFilter (searchtools.js?8d3a6407fa3397a32f1d85c1133aea51:188)
    at searchtools.js?8d3a6407fa3397a32f1d85c1133aea51:128
    at Array.forEach (<anonymous>)
    at Searchtools.init (searchtools.js?8d3a6407fa3397a32f1d85c1133aea51:127)
    at new Searchtools (searchtools.js?8d3a6407fa3397a32f1d85c1133aea51:84)
    at HTMLDocument.<anonymous> (searchtools.js?8d3a6407fa3397a32f1d85c1133aea51:431)

System information (as much as possible)

• Joomla 4 alpha 1
• PHP 7.0.25-1+ubuntu16.04.1+deb.sury.org+1
• MySQLi 5.7.20-0ubuntu0.16.04.1

Additional comments

• Problem seems to be with chosen multiselect only
• Also, the clear button does not work