Calculation to display Selected month and Previous month|| Datetrunc & Dateadd

Provide an option to choose month-year to user
and display selected month value and
previous month value

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For suppose,
when user selects
May 2018 - need to display may and apr values

Create parameter with date as datatype

Calculated filed to display selected month

datetrunc -
returns the starting value based on the
datepart

order date format: mm/dd/yyyy

dateadd('month',-1,[Choose Month-year]) -
returns previous month

selected month
if DATETRUNC('month',[Order Date])=DATETRUNC('month',[Choose Month-year]) then [Sales] END

previous month
if DATETRUNC('month',[Order Date])=DATETRUNC('month', dateadd('month',-1,[Choose Month-year])) then [Sales] END

[albertoalarcon]

As a new user, this video was great thanks fo it.
One question, is it possible to set the value of the "Choose Month-Year" from the a dashboard with Actions?
What I want to do is to dynamically set the "Choose Month-Year" value by selecting a bar from a "bar graph" which has data for each month-year value.
Hope I made myself clear about my question.

[praveenprakash]

how to do same when two parameters Dynamically
1.YeaParameter...2012
2.MonthParamter...Aug

Then I need Current month vs prev month sales like "Aug 2012 vs July 2012 sales KPI"
Note: I can do it when single parameter Like Nov 2012 as Single parameter using Datetrunc

[mohamedabdellatif]

Can we change the format of the parameter to be list instead of calender??

[technoscopy]

Hello sir I have small doubt if I give current month January 2021 does previous month show Dec 2020

[jessejacob]

can you show a video of how you created the month-year parameter?