Date Time Filter

I created a duplicate column (let's call this B) and changed the format to hh:nn of a datetime (mm/dd/yyyy hh:mm:ss) column. I also have a column (let's call this A) whose values are 0 or 1. I want to display, in a table, column A whose value is 1 and column B whose value is less than let's say 12 for any selected date. 

My measure I created.. 

FILTER(Main, (Main[A] = 1 && HOUR(Main[B]) < 12)) but I am getting an error that says,  "The expression refers to multiple columns. Multiple columns cannot be converted to a scalar value."

Thank you in advance!