Problems navigating folders when using FileSystem split view

[larspet]

Tested versions

• Reproducable in v4.4.dev.custom_build [a40fc23]
• Works fine in 4.4.dev6 and earlier

System information

Windows 11

Issue description

There's a few different problems, but I assume they are all related.

When using a folder structure like the one above, and navigating using the window to the right (not the tree view on the left):

• Cannot navigate to any subfolder from res://.
• From res://a/, clicking .. works, but the a folder will still be highlighted in the tree, instead of res://.
• From res://x/, clicking .. works, but the a folder (always the first subfolder) will be highlighted instead of res://.
• From res://a/b/ (or any folder at a depth of 2), clicking .. will not work.
• Navigating to or back from a folder at a depth of 3 or deeper works as expected.

Note: In all of these cases, the text field showing the current folder path is correctly updated.

Steps to reproduce

As described above.

Minimal reproduction project (MRP)

n/a