To Use the Search Tool

Select the property on which to search and any criteria. Add it to the search list by using the Add button.
To transform only buildings with build after 1950 select the property citygml_year_of_construction set the operator to greater than and write the date into the value field.
Click the Add button to apply this filter.
Feature classes with advanced search criteria will be shown with a hint next to the class name as shown below.

Tip: More filters can be added to better restrict the search.