Using an expression to group

Using Report Builder 3.0. 

There are two types of records to display. If GroupType = 1 group by Fields!PWO.value if GroupType = 2 group by Product and Price.

Parent Group is grouped on GroupType and child groups on expression as follows.

=IIF(Fields!GroupType = 1, Fields!PWO.value, Fields!Product.value) -------- this works.

What I really need is 

=IIF(Fields!GroupType = 1, Fields!PWO.value, Fields!Product.value And Fields!Price.value) -------- this does not work.

Is it possible to group on two different field values in an expression?

If so what should "Fields!Product.value And Fields!Price.value" look like?