Hi Vamsi

By specializing I suppose you mean modify the Dashboard content displayed.

There will be a system page("OperatorID") on clipboard which will contain the user's access group.

We can modify the section's layout rendered by making use of the above property.

First check which template is rendered for your Dashboard. In my case it is "pyUserDashboardTemplateRightColumn"

In that section define "OperatorID" page in Pages and Classes tab

Now in the template which is rendered add all the required content to be displayed for multiple AccessGroups. 

On the layouts added for different access groups add visibility condition based on their access group as below

Let me know if I've misunderstood your requirement.

I think you are talking about providing option for publishing-to-access_group. For customizing this option, you need to override the data-transform 'pyUserDashboardLoadList' and append another page with values for '.pyOwnerType' and '.pyOwner'.

Please let me know if you need more details.