You'll want to store the date-values in their own view so that they can be easily referenced multiple times.

Encapsulate the current filter in an OR statement, with a second parameter added that mirrors the first but checks for the same value range minus 365 days from the start/end points:

OR ( 1st AND statement describing the desired time-frame , 2nd AND statement describing the time-frame subtracting 365 days from each value) .