OBLPN label - Expression to get a value from a list of values

Summary:

Hi,

We're trying to design an OBLPN label and need this:

1) Orders at detail level can have 2 possible values on order_detail.cust_field_1 (Let's say "X" and "Y")

2) Allocations are cubed and can have many items on an OBLPN, these details can have any of these 2 values. For instance, an OBLPN can have 2 items: one of them with order_detail.cust_field_1="X" and the other one with order_detail.cust_field_1="Y"

Is there a expression that we can use to show if the OBLPN has a detail with order_detail.cust_field_1="X"?

Currently I'm using this expression on label designer: