I assume this is what you are looking for

You have already been basically provided answer for this, pick "correct" "formula" (these do not evaluate dynamically) and add additional check for "hi"
Names Default To Here(1);
dt = New Table("Untitled",
Add Rows(3),
New Column("Column 1", Character, "Nominal", Set Values({"hello", "bye", "bye"})),
New Column("Column 2", Character, "Nominal", Set Values({"hello", "bye", "bye"})),
New Column("Column 3", Character, "Nominal", Set Values({"hello", "hello", "bye"})),
New Column("Column 4", Character, "Nominal", Set Values({"hello", "a hello a", "bye"})),
New Column("Column 5", Character, "Nominal", Set Values({"hello", "bye", "bye"}), Set Display Width(75)),
New Column("Column 6", Character, "Nominal", Set Values({"hello hello hi", "hi hi hi hi", "bye"}))
);
dt << new column("C", numeric, continuous, formula(
If(Row() == 1,
dt = Current Data Table();
rangelow = 1;
rangehigh = 6;
);
res = Filter Each({val}, dt[Row(), Index(rangelow, rangehigh)], Contains(val, "hello") | Contains(val, "hi"));
N Items(res);
));
-Jarmo