Re: trying to get main domain header to match subdomain header
You will have to have a separate theme for your subdomain, and hard-code the links to go back to your root domain.
The way I did this, was to have a “buddypress-home” theme, and a “buddypress-sub” theme. The sub theme is basically a copy of all of the files from the “buddypress-home” theme, but without home.php, an edited style.css to change the name of the style, and a modified header.php which I will explain below.
The home theme is activated only for the root blog, the sub theme for all others.
In the header.php file for the sub blogs, I used
$bp->root_domain as the destination for each link, plus whatever slug was appropriate (MEMBERS_SLUG, BP_GROUPS_SLUG, BP_BLOGS_SLUG).
I also went ahead and made the BP_BLOGS_SLOG link
class="selected" right away, that way when you’re in a sub blog, the appropriate tab is always shown as selected.