special pivot table

[#1]

Hello Guys,

i have a data source which looks like this:

Shop Month Group Sales

A 1 X 100

A 2 Y 150

B 1 Y 200

B 2 Y 180

Now i like to create a Pivot Table which looks like the following:

The problem is that in some cases the group of month 2 is not the same as in month 2.

Dimension Formula 1 Formula 2

Group Sales month 1 Sales month 2

X 100 150

Y 200 180

Can anybody help me?