How to expand drives in folder tree permanently?

My drives are listed in the folder tree.

I want my 500Gb drive to always be expanded automatically when I open directory opus.
I don't want every folder in the 500Gb drive to be expanded though.

Please help.

At the moment, only the top-level expansions are remembered, plus a special option for the This PC branch and another to automatically expand the current folder

To have the E:\ drive also expanded by default, you could make that the default starting folder and turn on the option to expand the current folder automatically.

(In the future, we will be improving things, so you can do what you want more directly.)