Using nested frontmatter in Dataview

What I’m trying to do

I’d like to track time spent on different projects so I can calculate my FTE (full time effort) at the end of each month using dataview. I’m a professor, so there are three categories of FTE - service, teaching, and research. Under each of those, I may have several subcategories. I would like for my dataview table to group by date and sum for each subcategory, category, and total FTE.

To test I made several notes with the following YAML (but different input)

    project1: 7
    project2: 1.5
    committee1: .5
    committee2: 2

I can get the subcategory data with the dataview inquiry:

sum(nonnull(rows.fte.research.project1)) AS "Project 1",
sum(nonnull(rows.fte.research.project2)) AS "Project 2",
sum(nonnull(rows.fte.service.committee1)) AS "Committee 1",
sum(nonnull(rows.fte.service.committee2)) AS "Committee 2",
FROM "Daily Notes"
GROUP BY file.cday AS "Date"

But to get the total of all research I tried adding:

sum(nonnull(rows.fte.research)) AS "Research"

but that didn’t work.

I don’t see anything in the documentation about being able to use the “parent” levels in the nested front matter. Does anyone have any suggestions?