title: How to disable entire screen sharing and allow only application window and browser tabs sharing in BigBlueButton?
body: <p>Using BigBlueButton for online classroom I want to allow moderators to share their browser tabs or a particular application but not entire screen. When we tap on the screen sharing button from BigBlueButton Html5Client demo  then we got three options (Your Entire Screen , Application Window , Chrome(Browser Tab in case of other browsers) Tab) as Follows. </p>
  
  <p><a href="https://i.stack.imgur.com/qUCSw.jpg" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/qUCSw.jpg" alt="enter image description here"></a></p>
  
  <p>My requirements is to restrict the sharing of entire screen (From first option). Can I achieve it by customising some settings of BBB or by changing code of client demo application? 
  I seen this <a href="https://docs.bigbluebutton.org/2.2/customize.html#disable-screen-sharing" rel="nofollow noreferrer">Disable screen sharing</a>, But this option is disabling all options. </p>