Someone asked how he could find the start of the current month in a different year. He had a report that contained a parameter that selected a year, say 2007. He wanted to find the beginning of the current month, say May, in that year. So what he wanted was the string "May 1, 2007" when the current date was May 26, 2018. And if the current date were October 5, 2023, he would want the string to read "October 1, 2007".
Whenever you talk about dates in Power BI, you have to know how dates are stored. In this case, the date table was created with the DAX function
Dates = CALENDAR(DATE(2001,1,1), TODAY())
That gives you a table named Dates with a column named ...