Thanks for your response!

The refresh condition given in pzExplorers section is When Declare_pzRecentsCache.pxUpdateDateTime Changes.

As per my understanding, the only way to acheive this is by appending (target Data WO instance) to the Declare Page Declare_pzRecentsCache. Since, the source activity that builds this Page-List is a Final Rule,I had tried implementing the below steps provided in one of the reference article links mentioned in my original post.
1) Call a PreActivity/DataTransform that sets the pxTrackThisDocument to true in harness primary page.
2) In @baseclass.pyAddRecentListItem, add pyRecordID that shows in Recents section. Now, it will be added in clipboard recents. 
3) The recents section in the portal is filtered with a When rule, so one must update pyShowRecents When rule that qualifies patient.

When executed above steps, it is observed that required page does not get appended to the Page-List Declare_pzRecentsCache. Also,had directly tried to append a Page to this Page-List through activity step. But, Pega does not allow to do so. This is where I am currently struck with my implementation. 

Kindly let me know any alternate that is available to acheive this. Thank You!