Is it a limitation for the levels and the Items?

[DuZhaoKun]

Customer reported that they have a Epic own 231 Features. And Each Feature has a lot of User stories and Tasks.
When the select the Epic as Type and add the filter for this Epic to list out the items belongs to it. The app just can show the Epic's level.
If the user select the Feature as Type and add a filter(Parent) to show all items under this Epic, The App could show all items.
Is it a limitation for the levels and the Items?