BuddyPress.org

@prashantvatsh Sorry to bother you, but I tried the following solution, and it is still not working:

First, I added the following code to my bp-custom.php file:

<?php

//The following creates avatar class in activity stream
//based on x-profile field data

function buddydev_create_avatar_class_based_on_field_data() {
    
	$user_id = bp_get_activity_user_id();
	$title = xprofile_get_field_data('25', $user_id); // field ID or name
	$title = strtolower( $title );	
	$class = $title.'avatar';
	
	echo $class;
}

add_action( 'create_activity_avatar_class_based_on_field_data', 'buddydev_create_avatar_class_based_on_field_data', 10, 1 );

?>

Then, I added the following as a class inside the div tag for activity avatar in my buddypress/bp-templates/bp-legacy/buddypress/activity/entry.php file:

<?php do_action( 'create_activity_avatar_class_based_on_field_data'); ?>

Yet still it is not working. Did I put the do_action in the wrong file?