Possible to use expressions with guide_axis_nested()?

[gallagherman]

I can use expressions in scale_x_discrete() normally by setting labels = expression(...), but when use guide = axis_nested, using labels doesn't work anymore, because multiple labels are needed and I think the labels are taken directly from interaction() or weave_factors(). How can we use expressions with nested axis labels? Or is there a way to pass multiple custom label elements with expressions to weave_factors?

Expressions in labels Example:

# Single category, not nested data
data <- data.frame(
  Category = factor(c("A", "B", "C", "D")),
  Value = c(10, 20, 15, 25)
)

ggplot(data, aes(x = Category, y = Value)) +
  geom_col() +
  
  scale_x_discrete(labels = expression(
    Category~alpha,
    Category~beta,
    Category~delta,
    Category~gamma)
  )

[teunbrand]

Yeah that's right, the text itself is used to parse out the different hierarchy levels, which doesn't work with expressions.
I'm not planning to do any updates to guide_axis_nested(), as I'm working on something similar using functionality that now only lives in dev-ggplot2. Until that arrives, I'm afraid this isn't possible.

[teunbrand]

I'll close this as 'not planned' for now