Assuming you know how to filter on multiple fields using "and(,,)" ...

What you should do is create a Calculated Column called PickSeqMatch like this

FIND("P",{Picking Seq} ,1) +
FIND("Q",{Picking Seq} ,1) +
FIND("T",{Picking Seq} ,1) +
FIND("Z",{Picking Seq} ,1)

The result of this formula will be 0 if there are no matches, and it will be higher than 0 if there is at least one match.

Then include in the filter the expression

PickSeqMatch > 0

Does this help?

Steve