Or, to check for multiple criteria in the same column, you could use a
formula like:
=OR(D2="A",D2="B",D2="C")
Or list the multiple criteria on the worksheet, then check if the value
in the current row is in the list, e.g.:
=COUNTIF($K$2:$K$4,D2)>0
With either formula, filter the helper column for TRUE.