https://community.servicenow.com/thread/253728
Hi Harry,
Have this script in the onBefore transform script
if(source.u_field1 == '' && source.u_field2 == '' && source.u_field3 == '')
{
ignore = true;
}
you will have to repeat the AND condition for all the fields you wanted to check with
Mark Correct if this solves your issue and also hit Like and Helpful if you find my response worthy based on the impact.
Thanks
Ankur