How to get current month column in calculated table

mith_tina , Try measure like example

MTD =
var _max = if(isfiltered('Date'),MAX( 'Date'[Date]) , today())
var _min = eomonth(_max,-1)+1 ,
return
CALCULATE([net] ,DATESBETWEEN('Date'[Date],_min,_max))

Last Month =
var _max1 = if(isfiltered('Date'),MAX( 'Date'[Date]) , today())
var _max = eomonth(_max1,-1)
var _min = eomonth(_max1,-2)+1
return
CALCULATE([net] ,DATESBETWEEN('Date'[Date],_min,_max))

or

MTD Sales = CALCULATE(SUM(Sales[Sales Amount]),DATESMTD('Date'[Date]))
last MTD Sales = CALCULATE(SUM(Sales[Sales Amount]),DATESMTD(dateadd('Date'[Date],-1,MONTH)))
last month Sales = CALCULATE(SUM(Sales[Sales Amount]),previousmonth('Date'[Date]))
next month Sales = CALCULATE(SUM(Sales[Sales Amount]),nextmonth('Date'[Date]))

Power BI — Month on Month with or Without Time Intelligence
https://medium.com/@amitchandak.1978/power-bi-mtd-questions-time-intelligence-3-5-64b0b4a4090e
https://www.youtube.com/watch?v=6LUBbvcxtKA