Re: Modifiying Group Homepage
You have two options:
1) Use a child theme to override the group header
Copy “/bp-themes/bp-default/groups/single/group-header.php” to your child theme’s directory keeping the directory structure intact.
Make your modifications there.
If you don’t know what a child theme is, read up here:
Stick with this method if you’re unfamiliar with WP’s actions and hooks.
2) Use BP hooks to add content to the group header
There are multiple hooks in the group header template that you could inject your content with.
The following two are probably what you’re after:
You could create your own functions and hook into these actions from your child theme’s functions.php.
If what I’m saying is completely foreign to you, read up on this: