Rule for complex table tree in syclo

Hi All,

I am working on a rule on complex table tree in Service Manager - Reference object.

At present the complex  table tree in the screen is displaying the complete list of ibase.

My requirement is to display only the ibase which is selected along with the Service Order. Since its a complex table tree hence the cascade parent field in not present so do I need to create an update rule for this?

Can anyone please suggest me the approach I should follow in the rule to achieve this functionality.

Thanks

Neha