Dax issue

TechInayam , if there is selection , you can use datesmtd

MTD Sales = CALCULATE(SUM(Sales[Sales Amount]),DATESMTD('Date'[Date]))

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

MTD, LMTD  Based on Today

MTD Today =
var _min = eomonth(today(),-1)+1
var _max = today()
return
CALCULATE([Net], FILTER('Date','Date'[Date] >=_min && 'Date'[Date] <= _max))

LMTD Today=
var _min = eomonth(today(),-2)+1
var _max1 = today()
var _max = date(year(_max1),month(_max1)-1, day(_max1))
return
CALCULATE([Net], FILTER('Date','Date'[Date] >=_min && 'Date'[Date] <= _max))

LYMTD Today =
var _min = eomonth(today(),-13)+1
var _max1 = today()-1
var _max = date(year(_max1)-1,month(_max1), day(_max1))
return CALCULATE([Net], FILTER('Date','Date'[Date] >=_min && 'Date'[Date] <= _max))

MTD Yesterday =
var _max = today() -1
var _min = eomonth(_max,-1)+1
return CALCULATE([Net], FILTER('Date','Date'[Date] >=_min && 'Date'[Date] <= _max))

Time Intelligence, Part of learn Power BI https://youtu.be/cN8AO3_vmlY?t=27510
Time Intelligence, DATESMTD, DATESQTD, DATESYTD, Week On Week, Week Till Date, Custom Period on Period,
Custom Period till date: https://youtu.be/aU2aKbnHuWs&t=145s