once you place a subreport in your main report right click and select chang e sub-report links

 

You will need to link the subreport based on the formula move the Formula Field from Avaiilable fields to Fileds to Link  Once Done a Sub-Report parameter field will be created below left with name {?PM-FIELDNAME}

 

In record selection formula of subreport you will need to check the sub-report parameter which will start with {?PM-Name} with table field name to statisfy the condition.

 

 

Cheers

Rahul