Take a close look at the figure of A Minor. The positioning of the fingers can be used to play several chords depending on how far down the fretboard you move. Here are several examples of the notes relating to the A Minor figure.
Knowing the figure of A Minor and how the theory works….can you find another minor chord using the figure? This is the trick, keeping the same figure and moving up and down the fretboard resulting in a different note. Familiarize yourself with this and you will have no trouble finding the different chords all on your own just with this bit of theory.