Layout Combined fields

You just need to take a look at the date_entered_by, available on all record.php.

              array (
                'name' => 'date_entered_by',
                'readonly' => true,
                'inline' => true,
                'type' => 'fieldset',
                'label' => 'LBL_DATE_ENTERED',
                'fields' => 
                array (
                  0 => 
                  array (
                    'name' => 'date_entered',
                  ),
                  1 => 
                  array (
                    'type' => 'label',
                    'default_value' => 'LBL_BY',
                  ),
                  2 => 
                  array (
                    'name' => 'created_by_name',
                  ),
                ),
              ),

Pretty much all regular field attributes work here, however you faced issues configuring field specific dependencies.

Kind regards