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.

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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