How to nest multiple subgenres without re-typing main genres

Hey all,

Sorry in advance for not knowing many technical terms; fiddling with Calibre is a new hobby.

I have a question about nested tags (or genres, in this case). I know that it's possible to nest tags by using a period as an indicator character (e.g., "Tags: Nonfiction.Cookbooks" will create the tag "Nonfiction," which can be expanded to "Cookbooks"). I've created a custom column called "Genres" with a similar nesting function, allowing for very granular classification hierarchies. This is mostly great, but the more layers in a nest, the less efficient and more annoying the input becomes, especially for multi-faceted works.

For example, I might classify Sister Outsider by Audre Lorde as "Genre: Nonfiction.Essays.Anti-Racism." But Sister Outsider is also about class, sex, feminism, age, etc etc. Right now, in the "Genres" section of my custom metadata, in order to add all those subtopics, I need to re-type "Nonfiction.Essays." for every single item. Consequentially, the Genres column ends up looking like…

Nonfiction.Essays.Anti-Racism, Nonfiction.Essays.Class, Nonfiction.Essays.Sex, Nonfiction.Essays.Feminism, Nonfiction.Essays.Age, Nonfiction.Essays.[Subtopic], Nonfiction.Essays.[Subtopic], Nonfiction.Essays.[Subtopic], etc etc

…that.

The left panel still looks good - "Nonfiction" expands to "Essays," which expands to all the items above that follow each iteration of ".Essays" - but the input process takes forever, and the Genres column itself becomes bloated and unreadable. Is there an input method I haven't discovered yet that I can make Calibre sort of "auto-nest" each subtopic? Something like:

Nonfiction.Essays.Anti-Racism|Class|Sex|Feminism|Age|etc|etc|

I've desperately tried all manner of separator characters, but I haven't stumbled across any that work. And while I acknowledge and agree that using individual tags as an alternative would be much less hassle, it just wouldn't spark joy the way my neat little nested hierarchies do.

Any ideas? Thanks a bunch!