DAX calculate relatively last month, quarter and year

I need to create 3 measures for distinct count of MerchantName in DimMerchant for last month, last 3 months, and last year of a given relative date.

Example:

For DateValue = 4/1/2024 (date type MMddyyyy)

LM: count of merchants in 3/1/2024

L3M: count of merchants in 3/1/2024, 2/1/2024 and 1/1/2024

LY: count of merchants between 3/1/2024 and 4/1/2024

MerchantInternal# measure (current attempt):

CALCULATE(
    DISTINCTCOUNTNOBLANK('DimMerchant'[MerchantName]),
    FactTransaction
)

Table relationships:

• Merchant one to many to FactTransaction on MerchantName
• DimDate one to many to FactTransaction on DatePK

Example data input for testing:

1. DimDate (one to many to FactTransaction on DatePK)

2. DimMerchant (one to many to FactTransaction on MerchantHK)

3. FactTransaction (Main fact table where DimDate and DimMerchant have relationship)

Do have a look at the DAX Time intelligence functions.

Here is an example of what your measures could look like:

// base measure
# Merchant =
  CALCULATE(
    DISTINCTCOUNTNOBLANK(DimMerchant[MerchantHK]),
    FactTransaction
  )

// Last Month or Previous Month
# Merchant LM = CALCULATE([# Merchant], PREVIOUSMONTH(DimDate[DateValue]))

// Last 3 months (not including current selected month)
# Merchant L3M =
  CALCULATE(
    [# Merchant],
    DATESINPERIOD(DimDate[DateValue], MAX(DimDate[DateValue]) - 1, -3, MONTH)
  )

// Last 12 months (not including current selected month)
# Merchant LY =
  CALCULATE(
    [# Merchant],
    DATESINPERIOD(DimDate[DateValue], MAX(DimDate[DateValue]) - 1, -12, MONTH)
  )