create custom action & view in SugarCRM 7.x

No, you can't, you need to include #bwc for all backward compatible modules, while for sidecar modules you can use urls you mentioned. I suggest you to migrate your 6.x compatible modules into SugarCRM 7.x.

Hi Ivica Nedeljkovic

Thanks for the reply. I think I didn't explained my question as well as it I should have. 

Actually I have created a custom module in SugarCRM 7.7.0.0. And I need to create a custom action with a custom form view for that action.

How can I do that? 

This is called a custom layout for Sugar 7 -  described here - http://support.sugarcrm.com/Documentation/Sugar_Developer/Sugar_Developer_Guide_7.7/User_Interface/Layouts/Creating_Layo… . To create a 'helloworld' layout for your module, in custom/modules/<module/clients/base/layouts/helloworld/helloworld.php, put the following file:

<?php

$viewdefs['<modulename>']['base']['layout']['helloworld'] = array(
    'components' => array(
        array(
           'view' => 'helloworldview',
       ),

    ),
    'type' => 'simple',
    'name' => 'base',
    'span' => 12,
);

Then, to create the view, in custom/modules/<module/clients/base/views/helloworldview/helloworldview.hbs, put the following:

<p> Hello world.</p>

I don't think you'll need a controller for this, but if you do, in custom/modules/<module/clients/base/views/helloworldview/helloworldview.js:

({
    className: 'hello world',
    

});

Then, when you navigate to http://{site_url}/#modulename/helloworld/  you'll see the html. If you navigate to http://{site_url}/#modulename/idofarecord/my_custom_view/ then you'll be able to put stuff in the controller to load it into the view.

Further reading:

Sugar Development - Extension and Sidecar Framework - YouTube 

Sugar Development - Add a Custom Dashlet - YouTube

http://support.sugarcrm.com/Documentation/Sugar_Developer/Sugar_Developer_Guide_7.7/User_Interface/Sidecar/ 

http://support.sugarcrm.com/Documentation/Sugar_Developer/Sugar_Developer_Guide_7.7/User_Interface/Layouts/Creating_Layo… 

http://support.sugarcrm.com/Documentation/Sugar_Developer/Sugar_Developer_Guide_7.7/User_Interface/Layouts/ 

http://support.sugarcrm.com/Documentation/Sugar_Developer/Sugar_Developer_Guide_7.7/User_Interface/Views/