// open all buddypress activity links in new tab
function vap_activity_links_target_blank($link) {
	$link = str_replace(' rel="nofollow ugc"','target="_blank" rel="nofollow ugc"',$link);
    return $link;

}

add_filter('bp_get_activity_content','vap_activity_links_target_blank',20);
add_filter('bp_get_activity_content_body','vap_activity_links_target_blank',20);
add_filter('bp_get_activity_parent_content','vap_activity_links_target_blank',20);
add_filter('bp_get_activity_latest_update','vap_activity_links_target_blank',20);
add_filter('bp_get_activity_latest_update_excerpt','vap_activity_links_target_blank',20);
add_filter('bp_get_activity_feed_item_description','vap_activity_links_target_blank',20);
add_filter('bp_get_activity_feed_item_description','vap_activity_links_target_blank',20);