ISU-RTP : Multiple Interval permissible rates execution sequence

Hi..

Need help.

As per requirement we have configured multiple Interval permissible rates in billing schema, but however I don't want to execute both rates one after another.

I want to use o/p of  interval permissible rate 1 & want to do some calculation in normal facts permissible rates in billing schema.

Then I want to use same o/p in another interval permissible rate 2.

In Billing schema rate sequence is as

1. Interval permissible rate 1

2. Facts permissible rate

3. Interval permissible rate 2.

While billing in runtime it is observed rates execution is as

1.Interval permissible rate 1

2.Interval permissible rate

3. Facts permissible rate.

Whatever sequence defined in billing schema interval permissible rates are getting executed first followed by other rates in schema.

Pls share experience as anyone tried with multiple Interval permissible rates in schema ?

Thanks in advance.