Please consider that this is a customization request and outside of our support scope. We will do our best to show you how to customize but we will not be able to implement the feature for you.
Actually, we do not change much when it comes to Buddypress. the only template php files that we override in the theme can be found in the folder below:
You can use the steps mentioned here to override those file to your Child Theme and add your changes there safely.