BP_Activity_Component::setup_nav( array $main_nav = array(), array $sub_nav = array() )

	public function setup_nav( $main_nav = array(), $sub_nav = array() ) {

		// Stop if there is no user displayed or logged in.
		if ( ! is_user_logged_in() && ! bp_displayed_user_id() ) {
			return;
		}

		// Determine user to use.
		if ( bp_displayed_user_domain() ) {
			$user_domain = bp_displayed_user_domain();
		} elseif ( bp_loggedin_user_domain() ) {
			$user_domain = bp_loggedin_user_domain();
		} else {
			return;
		}

		$slug          = bp_get_activity_slug();
		$activity_link = trailingslashit( $user_domain . $slug );

		$main_slug = ['just-me'];
		if ( bp_activity_do_mentions() )   $main_slug[] = 'mentions';
		if ( bp_is_active( 'friends' ) && bp_is_my_profile() )   $main_slug[] = 'friends';
		if ( bp_is_active( 'groups' ) && bp_is_my_profile() )    $main_slug[] = 'groups';
		if ( bp_is_activity_follow_active() && bp_is_my_profile() )    $main_slug[] = 'following';


		// Add 'Activity' to the main navigation.
		$main_nav = array(
			'name'                => __( 'Timeline', 'buddyboss' ),
			'slug'                => $slug,
			'position'            => 25,
			'screen_function'     => 'bp_activity_screen_my_activity',
			'default_subnav_slug' => implode( ',', $main_slug ),
			'item_css_id'         => $this->id
		);

		parent::setup_nav( $main_nav );
	}