DS GetMembers() and BEx condition - Do they work without conflict ?

Hi Experts

I have a Query with one Row - Customer and One Column - Sales . I have a condition in the Query for Top 3 Customers Based on the Sales Amount.

When I bring this Query to Design Studio , My initial View shows only 3 Customers ( as expected ). When I assign it to a Crosstab - it shows 3 customers ( as expected) .

But when I populate the customers using getMemberList() to a Listbox - I get all the customers.
When I write a script with getMembers() - I get all the Customers.

Question -

1.When the Query is restricted to only 3 customers , Shouldnt DS only fetch 3 customers all time?

2.If this is how getmember behaves, then the actual question is - For some purpose I want to pass this Top 3 customers from Design Studio to another Query as separate variables - How to achieve this without using getmembers() .

(I am using DS 1.5)

Thanks in advance for your valuable time,effort and answers