Hi neeenz,
You have "../my:tDReport" in your expression. This says that the tDReport field is /my:myfields/my:OrgChart/my:Manager/tDReport which is incorrect as per the information you provide. You should try using /my:myfields/my:temp/my:tDReport instead (or whatever the actual path is).
So it would be:
<xsf:assignmentAction ...