By default, we do not have this option. You can use the following function code. Please see the steps below:

Note: Make sure to have a complete site backup before proceeding

    1. Go to Appearance - Theme Editor.

    2. Under Select theme to edit, choose (BuddyBoss Child/whatever theme is active), then click Select.

    3. Below Theme Files, select Theme Functions (functions.php).

    4. Append the code just before the closing PHP tag “?>”:

function change_display_name_format($display_name_format) {
    // Change the display name format to 'last_name - first_name'
    $display_name_format = '%last_name% - %first_name%';
    return $display_name_format;
}
add_filter('bp_core_display_name_format', 'change_display_name_format');

    5. Click Update File to save the changes.

Note: Any modifications are considered as custom work already. Know more about our Support Policy here: https://www.buddyboss.com/support-policy/