Custom tab in page properties.

Hi @abhising23 ,

Please refer to this to create custom page Properties - https://medium.com/@mayursatav/extending-page-properties-in-aem-40891183df30 

And Use InheritanceValueMap in Sling Model to get page properties value for Component. - https://stackoverflow.com/questions/48079450/how-to-get-page-properties-using-sling-model-in-aem-6-3 

If you are using ACS AEM Commons you can use Hierarchical Page Property as well - https://adobe-consulting-services.github.io/acs-aem-commons/features/sling-model-injectors/hierarchical-page-property/index.html 

Hope this could help you !!!

Regards

Shiv

You don't need to write in Java to add a new tab in page properties. You can just override cq:dialog of your page component and add a new tab.

You can refer this document override section and apply same for you page component 
https://experienceleague.adobe.com/docs/experience-manager-65/developing/platform/sling-resource-merger.html?lang=en

In your case it would be /apps/core/wcm/components/page/v3/page/cq:dialog

To display data in Tab, you can refer this resource. Its been used in Live Copy Tab to show the status. Path : /libs/wcm/msm/components/touch-ui/propertiesdialog/livecopy/status