Hello @MausamS3 Welcome to the community
What is the Pega version you are working on? and is it Theme-Cosmos/UI-Kit ? or Constellation ?
Regardless of the UI methodology, the UI behaviour you are expecting is too complicated and involves heavy UI customization with custom controls or custom components. Difficult to maintain in future as well.
Rather jumping into the technical implementation upfront, let’s just focus on the business outcome you want to achieve and based on that you can see what best you can do OOTB. You may want to provide more details about the actual business requirement so that we can suggest a viable approach.
If you are in traditional UI, you can have a look at the Navigational Tree approach which you can find in the UI Gallery as shown below and see if you can utilize it,
If it’s a constellation, i am afraid it might not be possible exactly how you mentioned, but may be in a different way and that too after clearly understanding the business requirement.
Regards
JC