Dynamically Filter Table using DAX and SELECTEDVALUE() Function

Now, I want to filter records using slicer (I) last one month, (II) last 3 months, etc. for which I have created one configuration table (cfg_date_group_frequency) as below:

I've created the following additional measures to filter the data as below:

dynMonthValue =
    // get the number value that needs to be subtracted to create a data filter
    SWITCH(
        TRUE(),
        SELECTEDVALUE(cfg_date_group_frequency[DateGroupName]) == "Last 1 Month",   0,
        SELECTEDVALUE(cfg_date_group_frequency[DateGroupName]) == "Last 3 Months",  2,
        SELECTEDVALUE(cfg_date_group_frequency[DateGroupName]) == "Last 6 Months",  5,
        SELECTEDVALUE(cfg_date_group_frequency[DateGroupName]) == "Last 12 Months", 11,
        12 // this is the default number of data that should be returned
    )


avlMaxDate =
    // get the latest available date from the vwAnalyticsDashboard
    MAX(vwProcuementDashboard[import_date])


dynFromDate = 
    // calculate the date from which the data needs to be filtered
    VAR SelectedMonth = MONTH([avlMaxDate]) - [dynMonthValue]
    VAR SelectedYear = YEAR([avlMaxDate]) - IF(SelectedMonth < 1, 1, 0)
    RETURN
        DATE(SelectedYear, IF(SelectedMonth < 1, 12 + SelectedMonth, SelectedMonth), 1)


dynFiltProcurementDashboard = 
    // dynamically fetch only the selected times from the table
    RETURN
        FILTER(
            vwProcuementDashboard,
            vwProcuementDashboard[import_date] >= [dynFromDate]
        )

However, when I check the data MIN(dynFiltProcurementDashboard[import_date]) the records are not filtered. However, I have checked separately that all the other values are correctly populated.

As far as I have seen, this is a very standard and straightforward approach, but I am not sure what I am doing wrong. My questions:

1. Why is the table not filtered?
2. Is there a better way to achieve this?

I've posted the same question in StackOverflow Community but have not received any feedback yet! Sample database and .pbix file is available here at https://github.com/ZenithClown/SO-77125934