I am using a board as an accounts board. Each account has sub items.
Sub items has a status and then number columns.
I want to use a formula column on the main account to total the sub item number column but only include sub items with a certain status - lets say Done ( green)
The app Rollup Subitems can do that (almost ). The app can show the percentage (as a number) of statuses with a given label. Currently it doen not yet support the count, but we can add that very quickly. Let me know if you want us to add that capability.
Not sure what Monday support said, but to me the most simple way to do this is to add a formula column to subitems that shows the value only if the Done status is selected, and then create a Show Summary on parent Row column for the subitem formula column, which totals the amount in the subitem formula column, which will give you your desired result.