Complex Dax Measure - Help Needed

// This will return all the customers
// visible in the current context who
// in the selected period of time in the same
// location bought at least(!) one and the same
// product at least 2 times and the purchases were
// made within at most 90 days within each
// other. This measure is fully responding
// to all filters, so please interpret it
// carefully WITHIN THE CURRENT CONTEXT.
// Transactions is the main fact table connected
// to dimensions: Customer, Location,
// Product, Date (joins to Transactions
// on [Purchase Date]) via the standard
// *:1 one-way relationship.

[# Cust] =
var __sections =
    // partition the transactions
    // by customer, product and
    // location
    SUMMARIZE(
        Transactions,
        Customer[CustID],
        Product[ProdID],
        Location[LocID]
    )
// for each section, check if
// there are at least 2 transactions
// within at most 90 days of each
// other and if there are, include
// the section in the final set
var __qualifiedSections =
    FILTER(
        __sections,
        CALCULATE(
            // get all dates that are present
            // in the transactions for the
            // current section
            var __sectionPurchaseDates =
                SUMMARIZE(
                    Transactions,
                    Dates[Date]
                )
            var __datesIfNextDateWithin90Days =
                FILTER(
                    __sectionPurchaseDates,
                    // calc the days to next purchase
                    var __currentDate = Dates[Date]
                    var __nextDate =
                        MAXX(
                            FILTER(
                                __sectionPurchaseDates,
                                Dates[Date] < __currentDate
                            ),
                            Dates[Date]
                        )
                    var __daysBetweenDates =
                        __nextDate - __currentDate
                    return
                        __daysBetweenDates <= 90
                        &&
                        // this condition must be here
                        // since the next date is BLANK
                        // for the last date in question
                        __daysBetweenDates > 0
                )
            return
                NOT ISEMPTY(
                    __datesIfNextDateWithin90Days
                )
                
        )
    )
var __customersSurvivedCount =
    DISTINCTCOUNT(
        SELECTCOLUMNS(
            __qualifiedSections,
            "@CustID", Customer[CustID]
        )
    )
return
    __customersSurvivedCount