Build-Your-Own Package - Pricing Rule - Exclude Other Performances in Production Season

Hello,

I have built and tested the Build-Your-Own Package pricing rule from the pricing rule recipe book and that works as intended. 

However, the pricing rule also triggers when a booker selects seats from multiple performances of the same production (for example 10 tickets for five performances of A Christmas Carol).

Is there a way to limit the rule so that it only triggers when a certain number of unique productions are selected? (Two tickets for productions A, B, C, D and E)

Thanks,

James