User should be able to navigate downward in the hierarchy.

Please take a look at the prototype to get a sense of how it should behave.

Block Focus/Visual Cues

Transparency

You’ll notice below that the selected parent and all of its children are fully visible – everything outside of that is semi-transparent (in this example, 20% opacity). This helps to draw the eye to the current selection, without losing focus of the wider picture.

Selection Indication

A selected block that has children gets a strong focus border (blue) and each child on the next level gets a dotted outline that hints at what’s inside.