Some time ago a breadcrumbs path bar in all file dialogs in Pantheon (like “Open“ or “Save” dialog) stopped working. It displays a current folder right, but when I try to click on it to move, for example, one folder up, it always throws me into my home folder, no matter what folder I click. “←” and “→” works fine, but breadcrumbs not, so I can't go to parent folder and I forced to click all my way from home folder every time. Any suggestions how can I fix it?
There are known regressions/issues with the filechooser breadcrumbs. See https://github.com/elementary/files/issues/1226 which matches your problem I think. This will not be fixed in the next release - which is imminent but https://github.com/elementary/files/pull/1136 will be fixed.
Hopefully your issue will be fixed in the following release in about a months time.
A work around is to use the keyboard shortcut UpArrow to navigate to the parent directory.