function wbcom_filter_activity_feed_by_date( $args ) {
    // Get the current date and calculate the date for 7 days ago.
    $seven_days_ago = date( 'Y-m-d H:i:s', strtotime( '-7 days' ) );

    // Modify the query to show only activities from the last 7 days.
    $args['date_query'] = array(
        array(
            'after' => $seven_days_ago,
            'inclusive' => true,
        ),
    );

    return $args;
}
add_filter( 'bp_after_has_activities_parse_args', 'wbcom_filter_activity_feed_by_date' );