How to Allow few websites

How to Allow few websites and block all other websites in firewall ?
actually i want to make the firewall policy according to whitelist and Blacklist.

i want to allow Black list users only to browse gmail and yahoomail,
white list users will allow all the websites,
as there is no whitelist and black list in mikrotik, i have just named to
differentiate the users class.

any suggestion will be highly appreciating.
thanks

This is so many time repeated question here so should rather read other relevant threads instead asking again…