All Screener filters (and data) are calculated on the time interval applied on the Screener’s toolbar (unless it is already predefined in the filter name).
E.g. if you set the Screener interval to 5 minutes, then all Screener filters will show the data for the symbol in the same way as if you were looking at it on a 5-minute chart.
However, the "Change 15m" filter is always calculated on a 15-minute interval and does not depend on the timeframe you set on the Screener. On any interval, such filters will show the value for the interval that is specified in its title.
At the moment, multiple intervals  cannot be applied for different columns of the Screener simultaneously.