DAX code for creating a new column - different time points

[Anonymous]

I am trying to create a new column (Variable 3) based off of the ID, Time point, Variable 1, and Variable 2 in the table below. I want to create a new column (Variable 3) which copies the value of Variable 2 ONLY IF the ID has a value of 1 for Variable 1 at Time point 0, otherwise Variable 3 will remain blank at all time points for that ID.

So I would want my resulting table to look like this:

Does anyone know what the DAX code would be to create this column? 

Thanks

[KHorseman · Accepted solution]

Let me see if I understand correctly. If there is a row for this ID where Time point = 0 and Variable 1 = 1, always copy Variable 2 for that ID. If not leave it blank. Right?

Variable 3 = VAR tp1 = COUNTROWS(
	FILTER(
		ALL(TableName),
		TableName[ID] = EARLIER(TableName[ID])
		&& TableName[Time point] = 0
		&& TableName[Variable 1] = 1
	)
)
RETURN IF(
	tp1 <> 0,
	TableName[Variable 2],
	BLANK()
)

You could do it without the VAR/RETURN by just cramming all that COUNTROWS stuff in where I reference tp1 below, but this is easier to read IMO.

[Anonymous]

Yes - this is exactly what I needed. Thank you so much!!