See Harmonized Scales for a lesson/tutorial about this test.
This proficiency test should be played with half notes at 60 BPM.
Start with the key of «C Major» so that you will only be playing natural notes.
Now descend backwards through the same shapes: Bdim, Am, GMaj, FMaj, Em, Dm, CMaj.
Next, start with the root inversion CMaj with the C on the 5th fret of the G string.
Last, complete the series with the final inversion CMaj with the C at the 8th fret of the E string. Again, ascending as well as descending, and shifting lower whenever you are too high on the neck.
Once you have harmonized the scale with all three inversions, play I-IV and IV-I cadences with all three inversions.
After you become comfortable with the key of C, pick another key and play that harmonized scale using all three inversions. You can just pick a key at random or proceed through the cycle of fourths/fifths (it isn’t necessary to practice all keys on every string-set, but it won’t hurt!).
You can harmonize the C Major scale on GBE following the steps above with half notes at 60 BPM.
Complete the exercise in other keys and with faster tempos.
Try to make some real music with the I-IV and I-V cadences: use slides, bends, and other articulations as well as introducing other intervening diatonic chords and notes.