Epic label autocompletion doesn't include labels from ancestor groups

When pressing ~ in a comment for epic, autocompletion dropdown for labels is triggered but it lists labels from epic's group only, not from all ancestor groups.

Reproducer:

• create a subgroup: group/subgroup
• create label grouplabel in group
• create an epic in subgroup
• in epic, add a comment and press ~. grouplabel is not listed in dropwodwn, but this label is listed in the right panel for editing epic labels.