Display data using FILTER formula not working

Question

I have this Google Sheets.

In sheet named Archive I have imported some tweets. In Sheet1 I have the following formula:

=FILTER('Archive'!A2:A;MMULT(SEARCH(TRANSPOSE(" "&A2:A&" ");" "&'Archive'!A2:A&" ");SIGN(ROW('Archive'!A2:A))))

What I would like to do is to display specific tweets from sheet Archive, containing specific keywords listed on Sheet1. This formula should work, but not in this case when I am importing data. All I get is a #N/A.

Am I doing something wrong?

Answer 1

As discussed on the sheet chat window, use:

=FILTER('Archive'!A2:A;MMULT(SEARCH(TRANSPOSE(" "&A2:A&" ");" "&TRIM('Archive'!A2:A)&" ");SIGN(ROW(A2:A))))

In short, the second argument of MMULT needs to have as many rows as there are columns in the first argument. Here is a spreadsheet that tries to describe MMULT used in this sort of way.

The TRIM part is to mitigate against spurious space characters that may be in the raw data.