@Aaronlim
you can do it with essential activities like
for each -iterating over the list
filter datatable
for each row for iterating the search results
add to collection for adding it to the list
also it can be done with linq, DatasetExtensions
YourDataTableVar.AsEnumerable.Select(function ( r ) r(ColumnnameOrIndex).toString.trim).Intersect(YourSearchStringList).toList
Used within an assign activity will return list of strings
Removing of duplicates can be done with additional use of Distinct()