Currently when you check on the Hide done option on a subset of subtasks and perform a Bulk edit operation all the tickets appear in the Bulk Edit screen(that includes issues which are done and not done).

Steps to replicate:

1. Select an issue that is populated with multiple subtasks, some of which are Done and others not done.
2. Select Hide Done on the subtasks dropdown to show only unresolved issues.
3. Select Bulk edit on the Subtasks dropdown to bulk edit these open issues.
4. All resolved and closed issues appear once again in the following screen. Screen recording attached.

Suggestion

Hide all the done issues in the Bulk edit screen when the Hide Done option is checked. 

Workaround

1. Open an issue with subtask.
2. Open the subtasks dropdown and click View in search. An issue search will then open, showing all the subtasks on that issue, including the done tasks.
3. In the Basic search, add the Resolution field and filter for Unresolved issues, this should show all the incomplete subtasks from the parent issue.
4. From here, open the dropdown menu at the top right of the issue search page and click Bulk Change all issues

You can now bulk edit all the incomplete subtasks from that ticket.