Cohort Analysis tutorial

Based on your post, I assume you want to find the following

1) How many new customer IDs were created each quarter?
2) How many of them purchased in the subsequent quarters?
3) Show the ratio counts as a percentage.

For the sake of better understanding, I will illustrate the workings step by step so that you will get started on this and you will be able to modify the codes on your own to suit your requirements.

Add the following Columns to your "Orders" table.

Step1: Add a calculated column for Customer's First Purchase Date

CustomerFirstPurchaseDate =
MINX (
    FILTER ( ALL ( Orders ), Orders[Customer ID] = EARLIER ( Orders[Customer ID] ) ),
    Orders[Order Date]
)

Step2: Add a calculated column for Order's Quarter No

OrderQtrNo =
VAR BaseYear =
    YEAR ( MINX ( ALL ( Orders ), Orders[Order Date] ) )
VAR OrderYear =
    YEAR ( Orders[Order Date] )
VAR MF = ( OrderYear - BaseYear ) * 4
RETURN
    Orders[Order Date].[QuarterNo] + MF

Step3: Add a calculated column for Customer's Q00

CustomerQ0 =
VAR BaseYear =
    YEAR ( MINX ( ALL ( Orders ), Orders[Order Date] ) )
VAR CFPYear =
    YEAR ( Orders[CustomerFirstPurchaseDate] )
VAR MF = ( CFPYear - BaseYear ) * 4
RETURN
    Orders[CustomerFirstPurchaseDate].[QuarterNo] + MF

Step4: Add a calculated column for Customer's 1st Quarter as text ( like 2014-Q3 etc...)

FirstQuarterOfCustomer =
Orders[CustomerFirstPurchaseDate].[Year] & "-Q" & Orders[CustomerFirstPurchaseDate].[QuarterNo]

Step 5: Add a calculated column for Customer's Returning Quarters

ReturningQuarterNo =
"Q"
    & FORMAT ( Orders[OrderQtrNo] - Orders[CustomerQ0], "00" )

Step 6: Add a measure for finding the count of active customers.

ActiveCustomerCount = DISTINCTCOUNT(Orders[Customer ID])

Step 7: Add a measure to find the total number of customers activated each quarter.

TotalCustomers =
CALCULATE (
    DISTINCTCOUNT ( Orders[Customer ID] ),
    Orders[ReturningQuarterNo] = "Q00"
)

Step 8: Add a measure to find the percentages

CA = DIVIDE([ActiveCustomerCount],[TotalCustomers],0)

Here is the result...