DAX: Cumulative Completion Rate with Month Slicer - powerbi

Question

I'm trying to calculate cumulative completion rate by all users over moths, the issue is that in the below table for ex when I filter on october it divides users who finished till october / all users except those who finished in November.
I have a dim_date table which is connect to the data table, the retaltion is between Date from dim_date and Completion Date from Data table
Also in dim date table im numbering the months 1,2,3,4 etc
ID
Completion_status
Completion Date
1
0
2
0
3
0
4
0
5
0
6
1
11/1/2022
7
1
11/1/2022
8
1
11/1/2022
9
1
11/2/2022
10
1
11/1/2022
11
1
11/6/2022
12
1
11/4/2022
13
1
11/2/2022
14
1
10/13/2022
15
1
10/14/2022
16
1
10/14/2022
17
1
10/13/2022
18
1
10/15/2022
19
1
10/13/2022
20
1
10/13/2022
21
1
10/13/2022
22
1
10/13/2022
23
1
10/18/2022
24
1
10/13/2022
25
1
10/13/2022
26
1
10/13/2022
27
1
10/13/2022
28
1
9/10/2022
29
1
9/8/2022
the formula I use
Completion% =
VAR comp rate = SUM(Table[completion_status]) / count(Table[ID])
Return
CALCULATE(Table[Completion%],filter(ALL(Dim_Date),Dim_Date[Month Number] <= MAX(Dim_Date[Month Number])))
the expected result when I filter
on september is 2/29 = 7%
on october is 16/29 = 55%
on November is 24/29 = 83%

Answer 1

Something like:
=
VAR SelectedMonth =
MIN( Dim_Date[Month Number] )
VAR CumulativeTotal =
CALCULATE(
COUNTROWS( 'Table' ),
FILTER(
ALL( Dim_Date ),
Dim_Date[Month Number] <= SelectedMonth
&& NOT ( ISBLANK( Dim_Date[Month Number] ) )
)
)
VAR CountAllRows =
CALCULATE( COUNTROWS( 'Table' ), ALL( Dim_Date ) )
RETURN
DIVIDE( CumulativeTotal, CountAllRows )
I'm presuming that Dim_Date[Month Number] is blank when Table[Completion Date] is blank.
You may want to replace ALL with, for example, ALLSELECTED, depending on your required set-up.