As an eg. there are 4 records i wanted to check how many null values are present for each records .
Page 1 / 1
Use an attribute exploder to split every attribute into a name/value pair. Then a Tester, to test that attr_name is the attributes you care about, and attr_value is null. Then Aggregator with Group By your ID, the number of features in the aggregation will be the count of null attributes.