Identify first Period with a Zero Amount Grouped by Entity

[ghwallis]

Hi, 

How do I identify the first Period with a zero Amount grouped by Entity in the following scenario. Thanks for responses.

Entity	Period	Amount
A	1	10.00
A	2	20.00
A	3	15.00
A	4	0.00
A	5	0.00
B	1	4.00
B	2	10.00
B	3	0.00
B	4	0.00
C	1	2.00
C	2	0.00
C	3	0.00
C	4	0.00

[binuacs]

@ghwallis is that what something you are looking for ? 

[ghwallis]

@binuacs, thanks for the response, this answer is a step closer, but I think does not account if the minimum value is non-zero. Sorry this may not have been clear from my initial post. 

[binuacs]

@ghwallis in that case adding a filter tool would solve the issue