I was able to find a solution for this. At first stage, we create a spring bean containing a search field value. Then use this bean in the NetSuite component. The correct flow is the following:
<spring:beans>
<spring:bean id="SearchBooleanField" name="SearchBooleanField" class="com.netsuite.webservices.platform.core_2013_1.SearchBooleanField" scope="prototype">
<spring:property name="searchValue" value="false"/>
</spring:bean>
</spring:beans>
...
<netsuite:search config-ref="Netsuite" searchRecord="EMPLOYEE_BASIC" bodyFieldsOnly="false" returnSearchColumns="false" pageSize="10" doc:name="Netsuite">
<netsuite:criteria>
<netsuite:criterium key="isInactive">#[app.registry.SearchBooleanField]</netsuite:criterium>
</netsuite:criteria>
</netsuite:search>