Dynamic rollback to previous 12 months based on date filter

Hello Team,

My report is made up of 9 pages. I have date column in the format of 2018.04(Year.Month). Data query mode is import method. Data source is consists of 3 years of data and counting. I need to put a slicer on date column to select by user such that all visualization in all pages of report should change accordingly. Here some visualizatons need to show last 12 months of data from which the month selected in slicer whereas some visulalizations need to show selected month values. If no selection is made I need to show current month, previous 12 months to current month in visualizations. 

Can some one suggest the approach for this rollback and default current month requirement for which slicer column is not in date format.