current year last month

[Pomna]

I need help with my code which is  as follows. I need to change 2019 and Oct so that it is not hard coded so that I will not have to go in every month to change the code. Thanks

Sum({$<[Work Date.autoCalendar.Year] = {'2019'}
,[Work Date.autoCalendar.Month] = {'Oct'}
,[IS.Activity Type] = {[Enhancing]}
,[Supported Location] =- {'04'}>}Hours)

[Pomna]

Is there a way I could modify my expression so that I would be able to filter data by date. For now my set expression only returns data for last month but I want to be able to compare last month and  last two month. Thank you for all the help