These filters let you pick a stocks based on the Directional Indicator (DI) formula.

If the +DI is above the -DI, the common interpretation is that the stock is going up.  To find stocks like that, set the minimum value for this filter to 0.  If the -DI is above the +DI, that is a sign of a downward trend.  To find stocks like that, set the maximum value for this filter to 0.

The exact formula for this filter is (+DI) - (-DI).  You can use this to make more specific queries.  For example, set the min value to 10 to find stocks where +DI is noticibly higher than -DI.  Or set the max value to -10 to find stocks that are going down more than a little.  This filter can be anywhere between -100 and 100.

The ADX, the +DI, and -DI are often used together, as in these examples.  The ADX confirms that there is a trend, and the +DI and -DI show the direction of the trend.  Relevant scans:  Stocks Trending Up Stocks Trending Down