BuddyPress.org

Delete your use of the add_action.

Research how to use a filter in WordPress.

Try :

function cami_field_value( $value, $type, $field_id ) {

     if ( $field_id == 123 ) {  // change 123 to the id of the field you want to change
         // adjust $value 
     }

     return $value;
}
add_filter( 'bp_get_the_profile_field_value', 'cami_field_value', 1, 3 );