Well, this is just a suggestion . . . Make a chart (I suppose it could be big) that shows the key of C major and all its notes across the fingerboard.

Now Asus2 is nothing but an A chord with a B stuck in instead of the third. Look up on your chart, and you'll see how this fits into the key of C. Do the same thing for Cmaj7. Cmaj7 is just a C chord with a B. See how it fits?

Do the same thing for tons of different chords and keys.