If you're using And (und) and Or (Oder) together, you'll usually want to use subclauses (not sure of the German name, sorry) to group them.
If you don't then, for example:
X or Y and Q or R
Could mean:
X (or Y and (Q or R))
Or:
(X or (Y and Q)) or R
Or:
((X or Y) and Q) or R)
etc. etc.
There are some examples of using subclauses in the Defining a Filter page of the manual.
(BTW, is it correct that "Oder" starts with an upppercase letter but "und" starts with a lowercase letter in the translation?)
You might also need to change the location filters, unless you only care about files directly below the two folders. Have a look at How to filter items by location or sub-folder.