Sorting

Click "Search & Filter". Then in the "Add More Filters" dropdown, choose "Number of Colors". Set this to >= 2, and click "Apply Filters".

By default, it's already sorted by Name (i.e. alphabetical), but if you've changed that, just click on "Name" to go back to that.

And of course, you can further filter to, say, a specific edition.

NOTE: The "Number of Colors" filter only cares about casting cost and not mana symbols in the textbox. In other words, it can't be used to check for color identity (for commander). So it won't find e.g. Alesha, Who Smiles at Death.

Hope this helps!