Hi, David.
This is relatively easy to achieve :)
You need to copy this file:
ROOT/components/com_community/templates/jomsocial/layouts/groups/single.php
to:
ROOT/templates/your-template/html/com_community/layouts/groups (if you don't have those folders - feel free to create them)
Then before line 72:
<h2><?php echo CActivities::truncateComplex($group->name, $titleLength, true); ?></h2>
You need to add php condition:
<?php if($group->id != 217) { ?>
It means if group ID is DIFFERENT from 217 (this is your group ID for which you want to hide title) then load code that is below. So when ID is = 217 title will be NOT displayed.
and after line 72 you need to close condition:
Final code should look like this:
<?php if($group->id != 217) { ?>
<h2><?php echo CActivities::truncateComplex($group->name, $titleLength, true); ?></h2>
<?php } ?>
If you want to add more groups to condition tehn:
<?php if(($group->id != 217) AND ($group->id != 218)) { ?>
Just add more AND with condition.