Owner/admins make an announcement then pin and "notify all members" so that they update the latest version of Telegram app, check @tgfiles
Group Owner enable Topics in the Group Info > Edit. (Only the Owner can enable/disable Topics)
Disable "Create Topics" in Global Permissions so that all members are restricted from being able to create Topics. (This should be done by the Owner because when it is disabled, the admin will also lose this right)
Enable "Create Topics" right for each Admin by the Owner of the group chat.
Topics can be pinned (up to 5 pins) so that they are always at the top, check @TheForum
NOTES
Topics are only for Groups with more than 200 members.
After the Topics feature is active, old messages won't appear on Topics, you have to switch to "View as Messages" mode in the 3-dot menu to the right of the group title.
Topics cannot be assigned for Groups that link to a Channel.
Safe, undoable. If you disable Topics, it will return to its original state.
Group Owner enable Topics in the Group Info > Edit. (Only Owner can enable/disable Topics)
Disable "Create Topics" in Global Permissions so that all members are restricted from being able to create Topics. (This should be done by the Owner because when it is disabled, the admin will also lose this right)
Enable "Create Topics" right for each Admin by the Owner of the group chat.
