The loading HTML for the activity page, which displays the message “Loading community updates. Please wait.”, can be found in the following structure:
<div id="bp-ajax-loader">
<aside class="bp-feedback bp-messages loading">
<span class="bp-icon" aria-hidden="true"></span>
<p>Loading community updates. Please wait.</p>
</aside>
</div>
If you want to add an id to the <p> tag, you will need to modify the relevant template files. The loader markup is typically found in these locations:
/buddyboss-theme/buddypress/activity/index.php/buddyboss-platform/bp-templates/bp-nouveau/buddypress/common/notices/template-notices.php
Editing these files will allow you to customize the structure of the loading message as needed.