I don't see any method to ignore parent\cache\, but include parent\classes\cache\ with only using Subdirectories to ignore in search.

I have 3 suggestions:

1. Set hidden attribute on directory parent\cache\ and use in Find in Files additionally Ignore hidden subdirectories.
2. Instead of having selected parent\ in Directory and using Subdirectories to ignore in search for some subdirectories specify in Directory all subdirectories of parent\ separated with ; in which Find in Files should search. This solution can't be used if there are files in parent\ which should be included, except Search subdirectories can be also disabled because of having all directories to search in specified in Directory.
3. Specify more precise in In files/types which files should be found to exclude the files in parent\cache\ if this directory does not contain files with a name being identical to file names in other directories to search.

Hint: Use an empty search string to get listed by Find in Files just the file names on experimenting to find the right find options.