You will want to have worked through Page One of this mini-series before tackling the exercises on this page.
D major chords have just one black key - the third, F sharp.
To play chords with black keys in them - especially to get your thumb onto a black key - your hand has to slide up towards the back of the keys.
You can't afford to be shy of playing up among the black keys like this! Any 'unnatural' feeling will soon wear off, and your playing will be much better for it.
Challenge yourself to name the inversions and the chord tones. It's not easy, but in the end you'll "know what you're talking about".
The up-to-speed video of the D major procedure got lost somewhere along the line - you'll have to do it yourself.
B flat is a funny-feeling chord - you have to be right up among the black keys just to play the root position.
Now, you have to be naming the inversions and chord tones (perhaps not all the time...).
Here's that procedure up to speed.
The procedure you have been practicing does lots of things for you.
Use the 'Three chords tones in three places' on any new chord whose look-and-feel is a bit of a puzzle, and their secrets will soon all be revealed!
Next, you go on to breaking up the inversions into rhythmic Broken Chord Patterns.