I have logged issue with BMC. Also, I found the Defect SW00280670 but that
is in version 7.0.02. I am able to see 'All Tasks' in task field in 7.6.03
and unable to set it to 'All Open tasks'.
Anyone who can see if it works as it should in 7.6.03 SP2?
I believe this is resolved in using Knowledge Article:KA288654
I will confirm once I have implemented the fix.