I am well aware of Groupcount() and Groupsummary(). These work on a more global basis.
If I put in Groupcount(series) it will tell me how many unique values I have in the Series field.
As an example, lets say I have two series, Series A that has two seasons, each with ten episodes. And Series B that has 4 seasons, each with twelve episodes.
With my proposed new function if I put in ItemCount(series).
Series A would return 20
Series B would return 48
If I were to enter ItemCount(season)
Series A would return 2
Series B would return 4
If I were to enter ItemCount(Series,Season=1,3)
Series A would return 10 (as it doesn't have a third season)
Series B would return 24 (season 1 and season 3 both have 12 episodes, hence 24)
Now lets say I have a 10 disc box set for a band. Each disc has 10 tracks.
If I enter ItemCount(AlbumKey(),Disc #) it would return 10
If I enter ItemCount(AlbumKey(),name) it would return 100
If I enter ItemCount(AlbumKey(),duration) it would return the length of the entire box set
If I enter ItemCount(AlbumKey(),duration,disc #=3) it would return the entire length of disc #3
And so on and so forth. I think this would come in extremely handy.