Adding separator in User Profile Display Name
When you have set the User Display Name to Custom fields in wp-admin>Ultimate Member> Settings> General> Users. By default, the custom fields displayed in the profile form do not have any separator. See the sample image below.

Sample image:

To add a separator between fields, you need to use a custom code. You can try the sample code below:
add_filter( 'um_user_display_name_filter', 'my_um_user_display_name_filter', 10, 3 );
function my_um_user_display_name_filter( $name, $user_id, $attrs ) {
if( $attrs == 1 ) {
$name = um_user( 'company_name' ) . ' | ' . um_user( 'first_name' ) . ' ' . um_user( 'last_name' );
}
return $name;
}
Result: