How to apply du (f.x.) to all sub directories except for some of them?

./a |-/bx1 |-/by2 |-/bz3 |-/bx4 |-/by5 

Now I want to apply du to all sub-folders except for /by2 and /bx4.

I can make it happen for one folder:

du --max-depth=1 --exclude=./by2 

but not for two.

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I found to related questions:

1. Getting size of directories and exclude some folders
2. Using --exclude with the du command

In (1) regular expressions are applied which won't work in my case - at least not comfortably. In (2) the exclusion refers to a full sub-directory. Essentially my question is:

Can I feed --exclude a list of files/directories and if yes, how?