Top values based on Aggr across multiple products and differing live dates

[Amen_90]

Hey Guys, 

I was hoping someone might be able to guide / help me. So I want to create an index chart for product sales which is based on live date that can be variable across different customers and products. 

Lets say in my example below I want to to know product growth based on the live date for a specific account that is July-22. 
Lets also say this is my Raw data below:

Date	Live_Date	Account	Product	Sales
Jan-22	July-22	A	Apple	1
Feb-22	July-22	A	Apple	2
Mar-22	July-22	A	Apple	3
Apr-22	July-22	A	Apple	4
May-22	July-22	A	Apple	5
Jun-22	July-22	A	Apple	6
Jul-22	July-22	A	Apple	7
Aug-22	July-22	A	Apple	8
Sep-22	July-22	A	Apple	9
Oct-22	July-22	A	Apple	10
Nov-22	July-22	A	Apple	11
Dec-22	July-22	A	Apple	12
Jan-22	July-22	A	Samsung	2
Feb-22	July-22	A	Samsung	4
Mar-22	July-22	A	Samsung	6
Apr-22	July-22	A	Samsung	8
May-22	July-22	A	Samsung	10
Jun-22	July-22	A	Samsung	12
Jul-22	July-22	A	Samsung	14
Aug-22	July-22	A	Samsung	16
Sep-22	July-22	A	Samsung	18
Oct-22	July-22	A	Samsung	20
Nov-22	July-22	A	Samsung	22
Dec-22	July-22	A	Samsung	24

I have figured out through reading the forms that I can grab the top sales value across all my dimension by running the following measure expression;

aggr(Top(Sum(Sales)),Product, (Date,(Numeric, ASCENDING)))

Which gives me a table that looks like this;

Date	Live_Date	Account	Product	Sales	Top
Jan-22	July-22	A	Apple	1	1
Feb-22	July-22	A	Apple	2	1
Mar-22	July-22	A	Apple	3	1
Apr-22	July-22	A	Apple	4	1
May-22	July-22	A	Apple	5	1
Jun-22	July-22	A	Apple	6	1
Jul-22	July-22	A	Apple	7	1
Aug-22	July-22	A	Apple	8	1
Sep-22	July-22	A	Apple	9	1
Oct-22	July-22	A	Apple	10	1
Nov-22	July-22	A	Apple	11	1
Dec-22	July-22	A	Apple	12	1
Jan-22	July-22	A	Samsung	2	2
Feb-22	July-22	A	Samsung	4	2
Mar-22	July-22	A	Samsung	6	2
Apr-22	July-22	A	Samsung	8	2
May-22	July-22	A	Samsung	10	2
Jun-22	July-22	A	Samsung	12	2
Jul-22	July-22	A	Samsung	14	2
Aug-22	July-22	A	Samsung	16	2
Sep-22	July-22	A	Samsung	18	2
Oct-22	July-22	A	Samsung	20	2
Nov-22	July-22	A	Samsung	22	2
Dec-22	July-22	A	Samsung	24	2

However, where I am struggling now is when wanting the Top value to be that of the Live date. Bearing in mind that I have multiple accounts which all have different live dates so I cannot hard code it as a set. When I apply the following expression to try get the top value as per the live date I get it filled in with Zeros as per the aggr expression I am using:

Aggr(top(Sum(if(Date>= Live_Date, Sales))),Product,(Date,(Numeric, ASCENDING)))

The table looks like this:

Date	Live_Date	Account	Product	Sales	Top
Jan-22	July-22	A	Apple	1	0
Feb-22	July-22	A	Apple	2	0
Mar-22	July-22	A	Apple	3	0
Apr-22	July-22	A	Apple	4	0
May-22	July-22	A	Apple	5	0
Jun-22	July-22	A	Apple	0	0
Jul-22	July-22	A	Apple	7	0
Aug-22	July-22	A	Apple	8	0
Sep-22	July-22	A	Apple	9	0
Oct-22	July-22	A	Apple	10	0
Nov-22	July-22	A	Apple	11	0
Dec-22	July-22	A	Apple	12	0
Jan-22	July-22	A	Samsung	2	0
Feb-22	July-22	A	Samsung	4	0
Mar-22	July-22	A	Samsung	6	0
Apr-22	July-22	A	Samsung	8	0
May-22	July-22	A	Samsung	10	0
Jun-22	July-22	A	Samsung	12	0
Jul-22	July-22	A	Samsung	14	0
Aug-22	July-22	A	Samsung	16	0
Sep-22	July-22	A	Samsung	18	0
Oct-22	July-22	A	Samsung	20	0
Nov-22	July-22	A	Samsung	22	0
Dec-22	July-22	A	Samsung	24	0

What I think is going wrong here is that that the sales have been reduced to just from July onwards, but the function is filling in dates that are not in scope with 0, so top returns the 0.  I've tried added null() to the sum if statement but nothing seems to be working for me.

What I would like my table to look like is this (where the - is null):

Date	Live_Date	Account	Product	Sales	Top
Jan-22	July-22	A	Apple	1	-
Feb-22	July-22	A	Apple	2	-
Mar-22	July-22	A	Apple	3	-
Apr-22	July-22	A	Apple	4	-
May-22	July-22	A	Apple	5	-
Jun-22	July-22	A	Apple	0	-
Jul-22	July-22	A	Apple	7	7
Aug-22	July-22	A	Apple	8	7
Sep-22	July-22	A	Apple	9	7
Oct-22	July-22	A	Apple	10	7
Nov-22	July-22	A	Apple	11	7
Dec-22	July-22	A	Apple	12	7
Jan-22	July-22	A	Samsung	2	-
Feb-22	July-22	A	Samsung	4	-
Mar-22	July-22	A	Samsung	6	-
Apr-22	July-22	A	Samsung	8	-
May-22	July-22	A	Samsung	10	-
Jun-22	July-22	A	Samsung	12	-
Jul-22	July-22	A	Samsung	14	14
Aug-22	July-22	A	Samsung	16	14
Sep-22	July-22	A	Samsung	18	14
Oct-22	July-22	A	Samsung	20	14
Nov-22	July-22	A	Samsung	22	14
Dec-22	July-22	A	Samsung	24	14

Ultimately the this is going to be used in an indexed line graph from the Live date for each account. The functionality would require the user to select an account before the chart is displayed. 

Any help would be greatly appreciated.