As in D major, in B flat major - B flat and E flat - you have to get your hands up onto the black keys to play the triads. Even more so, in fact - your right hand thumb actually starts on a black key.
Go right ahead and play Pattern One ascending in B flat, once with 1-3-5 on root position (circle) chords, and once with 1-2-4 on the root position chords - where convenient.
Notice that, for clarity, the fingering on the keyboard is still on the white keys. You 'apply' the key signature and flatten white keys B and E, is shown by the key signature.
Rehearse these steps as you read them through.
And repeat. Do you find you are starting to hear the next chord in advance?
Pattern One descending is the exact mirror image of Pattern One ascending.
The pattern repeats seven time over a whole octave.
Practice with both root position fingerings, as in the video.
Now play Pattern One in B flat continuously up and down.
No fingering is indicated on the keyboard - just the notes. You use your familiarity with the two fingerings and the 'feel' of the key to get your fingers to the chords required.
Rehearse Pattern Two 'in your mind's eye', talking through the voice movement ("Top two notes both go up, middle one goes back down, bottom two come up..." etc.) using the music.
Note that you don't have to be able to read music to talk about whether the notes go up, down, or stay the same.
Be particular about this mental rehearsal - you've got to figure out your own fingering as well, so you need to have at least the movement sure in your head.
Now play Pattern Two in B flat, up and down continuously (if possible), using either 1-3-5 or 1-2-4 on the root position (circle) chords - but always 1-2-5 on the first inversion (triangle) chords.
You see how easy it is, when you're not told which fingers to use, to run out or just trip over yourself. Think about fingering calmly and logically. Practice makes perfect!
Now for some catch-up on Page Four of the series:
whole patterns in C and the hybrid Pattern Three.