How to combine multiple And and Or through method name

I agree with Oliver on long and unreadable method names, but nevertheless and for the sake of argument, you can achieve desired result by using the equivalency

A /\ (B \/ C) <=> (A /\ B) \/ (A /\ C)
A and (B or C) <=> (A and B) or (A and C)

So in your case it should look something like this:

findByPlan_PlanTypeInAndSetupStepIsNullOrPlan_PlanTypeInAndStepupStepIs(...)