The search/filter criteria box appears when filter criteria are defined as editable.
See SELECT tab in edit mode. Click on the operator and change it to the one fitting your needs. Then Click on the value to enter a proper one.
Automatic Update /Manual Update of Results
Change an operator and/or a value to filter on and results will be updated automatically. This is default setting.
In case reports have many filter criteria, the update will occur on each change. This may be annoying when many results are expected. In that case check "on user request" in report options.
Then you may trigger search by clicking search icon