Look up the first (and only) occurence of a value DAX

[MHB1980]

Hi, I have a table that looks like this. (There are a lot more of other columns aswell) but if could make a dax that applies to the colums in the example it would help for the whole report. 

I want to return _only_ the first line where the "HarvestAverageWeightClosing" goes from 0 to any number. The dataset contains multiple sitenames, unitnames and date. But it will always be a unique "first" date for each sitename and unitname. I have tried several soution, also with date filters, but it wont help as the values in some cases duplicates "forever" 

[amitchandak]

@MHB1980 , Create a new column like

flag=
var _min = Minx(filter(Table, [Sitename] = earlier([Sitename]) && [UnitName] = earlier([Unitname]) && [HarvestAverageWeightClosing]>0), [Date])
return
if(_min = [Date], 1, 0)

[MHB1980]

Thank you, it doesnt seem like I have permission to add columns. But I will present the soultion for somone with access.