Use the following formula to obtain the query you want.
In the reference it is explained by Ahab that
* can be used as boolean expressions, as
The solution with the
IFERROR (see revision history) is of no use in this case, unless you want to find a particular string:
=FILTER(Sheet2!A:F;IFERROR(FIND("Combat";A:A);0) + IFERROR(FIND("Uni";A:A);0))
0 when nothing is found, causing the formula to still function.
I've modified the example file to contain both solutions: Filter with Boolean
Google Product Forum, Boolean Expressions