Do you mean in Saved Search or Analytics?
Once approach
Col 1 This months amounts
Col 2 12 months Earlier
Your respective columns could be something like
COL 1 Formula DECODE(TO_CHAR({trandate},'Mon-YYYY'),TO_CHAR({today},'Mon-YYYY'),{amount},0)
COL 2 Formula DECODE(TO_CHAR({trandate},'Mon-YYYY'),TO_CHAR(ADD_MONTHS({today},-12),'Mon-YYYY'),{amount},0)