Creating SLA measure based on minimum Date

[mloy3]

Hi All, 

I been trying to do a computation for hours (no admin rights). I would ideally like to compute the difference in business days for
- each unique [Work Unit ID]'s [Task Unique key] 8060.1's [Work Unit Process Start Date] AND
- the same [Work Unit Id] has [Task Unique key] 13125.1 & 8067.1's MINIMUM [Work Unit Process Start Date]

I was able to create a custom Dimension for Date Error Flagged via
=aggr(min({<[Tasks.Task_Unique_Key]={13125.1,8067.1}>}[Work Unit Process Start Date]),[Work Unit Entity ID])

However, i was facing significant issues when i try to undertake the subtraction. This should be my output if i am successful. Thank you for your help!

Work Unit ID	Task Unique Key	Work Unit Process Start Date	Earliest Error measure	Date Error Flagged	Difference in Business Days
9509251	11534.1	6/24/2019	-	6/25/2019	-
9509251	12078.1	6/24/2019	-	6/25/2019	-
9509251	13125.1	6/25/2019	-	6/25/2019	-
9509251	8060.1	6/26/2019	6/25/2019	6/25/2019	2
9509251	8067.1	6/26/2019	-	6/25/2019	-
9509231	11534.1	6/24/2019	-	6/26/2019	-
9509231	12078.1	6/24/2019	-	6/26/2019	-
9509231	13125.1	6/26/2019	-	6/26/2019	-
9509231	8067.1	6/26/2019	6/26/2019	6/26/2019
9509231	8060.1	6/26/2019	-	6/26/2019	1
9509223	11534.1	6/24/2019	-	6/24/2019	-
9509223	12078.1	6/24/2019	-	6/24/2019	-
9509223	13125.1	6/24/2019	-	6/24/2019	-
9509223	8067.1	6/26/2019	6/26/2019	6/24/2019	-
9509223	8060.1	6/26/2019	-	6/24/2019	3
9509220	11534.1	6/24/2019	-	6/25/2019	-
9509220	12078.1	6/24/2019	-	6/25/2019	-
9509220	13125.1	6/25/2019	6/25/2019	6/25/2019	-
9509220	8060.1	6/25/2019	-	6/25/2019	1
9509220	8067.1	6/25/2019	-	6/25/2019	-

[mloy3]

this is what i came up with but i find that it works for some Work Unit Entity ID but not all.

if(match([Tasks.Task_Unique_Key],8060.1),

networkdays(aggr(min({<[Tasks.Task_Unique_Key]={13125.1,8067.1}>}[Work Unit Process Start Date]),[Work Unit Entity ID]),[Work Unit Process Start Date]))