Cascading Prompt disabled in the universe created from BEX Query

Hi Experts,

I have created the universe from BEX Query.

I have a reuqirement as explained below:

there are 3 objects: Region, Country, Branch.

So, when the user selects Region, the corresponding Country values needs to be displayed and then Branch.

So, for this I am trying to create Cascading Prompt in the universe, but Generate LOV has been disabled.

I would like to know is there any other option in the universe or WebI report where we can implement this feature.

Thanks in advance....

Please provide any solution as soon as possible.

Regards

Sindhu