your expression refers to two different tables and refers to table 2 twice for some reason. Do you want to find records from table 2 or records from table 1?
What is the relationship linking Table1 to table2?
One method might be to use sort records with the "re-order on summary field" option to put the groups with a zero value first or last in your report. Then there might be a way to use Omit Multiple records to omit them from a found set.