The idea goes you sum up all account entries that have a Level 1 of "revenue" and divide the value by revenue to get percent of revenue. However, the measure didn't quite work that way.
It's clear from this that the measure is filtering by reporting level, so the "total revenue" part of the measure is never actually calculating the total revenue, but only for that specific filter result.
I think this can be corrected by using ALLEXCEPT in the measure, but I've been unable to get it to work.
Edit : can't attach a .pbix to this post, account is probably too new.
The subcategories are being correctly divided by the revenue.
However, ALLSELECTED removes the year and month filters, so data is only correct at the highest level, and if you drill down, the numbers are being divided by the total revenue across all months rather than by the monthly revenue. I'm thinking that the correct implemention involves a way for the measure to ignore reporting levels, but keeping all other filters (e.g. month/year).
I recommend making a measure of the Sum of Revenue and using that instead of the root data. In that you'd put the filter "Chart of Accounts" criteria. That may be why the formula is not working for you.
Measures that pre-sum commonly used numbers work well and save future work.