We cannot hide attributes using business rules on the Issues or other custom subobjects, however, the disable attribute actions work as expected in locking the attribute.
Example of business rule for condition PROJECT NAME = 'name':
Grid view and Detail flyout show the attribute after publishing Business rule:
Clarity 16.2.3
The business rules capability to perform the Hide Attributes action is limited to the Object properties module currently. The hide actions will not work on the Grid view or the detail flyouts of the target object. This may be a feature in a future release.
Process to raise enhancement requests in Clarity: Enhancement Requests for Clarity