Hi Wajah
If the ProductMaster.SOH ,FromSOH and ToSOH are integers than it should work.
ProductMaster.SOH >= FromSOH or FromSOH = NullIdentifier()
and
ProductMaster.SOH <= ToSOH or ToSOH = NullIdentifier()
You also need to check the above highlighted condition because of that also you can get wrong output.
Best Regards
Devendra