How can I filter for specific combinations in Google Data Studio?

Question

I have a data set with multiple lines per person and the type of fruit they selected on a particular date. I would like to create a filter to show me people that selected specific combinations (i.e. apple and pear). Ideally I would like to be able to incorporate a date filter as well but this is a secondary need.

I tried using the following as a new field, as a metric, and as a calculated control field but I get the same error message for all of them:

CASE
  WHEN SUM(Apple) > 0 AND SUM(Orange) > 0 AND SUM(Pear) = 0 THEN 'Apple and Orange'
  WHEN SUM(Apple) > 0 AND SUM(Orange) = 0 AND SUM(Pear) = 0 THEN 'Apple'
  WHEN SUM(Apple) = 0 AND SUM(Orange) = 0 AND SUM(Pear) > 0 THEN 'Pear'
  WHEN SUM(Apple) = 0 AND SUM(Orange) > 0 AND SUM(Pear) = 0 THEN 'Orange'
  WHEN SUM(Apple) > 0 AND SUM(Orange) = 0 AND SUM(Pear) > 0 THEN 'Apple and Pear'
  WHEN SUM(Apple) > 0 AND SUM(Orange) > 0 AND SUM(Pear) > 0 THEN 'Orange and Pear'
  ELSE 'other'
END

I keep receiving this error message:

Metric expressions and aggregations are not allowed in this expression.

however I don't have any metrics included in the calculation.

Resources that might help:

• Picture of data layout:
  

• Sample Data (Google Sheets)

• Google Data Studio link