Embedding layers in an HStack, or a Horizontal Stack, allows you to stack layers in order horizontally. An HStack will take up the same amount of space as all of its child layers.
By default, an HStack centers all of its child layers horizontally along the x-axis and sets a spacing of 8 points between each one.
You can vertically align the centers of its sublayer within an HStack to position layers to the:
Top - All layers aligned to the top of the HStack
Center - All layers aligned to the vertical center of the HStack
Bottom - All layers aligned to the bottom of the HStack
Text Baseline - All layers aligned with the baseline of the largest Text layer in the HStack
You can also customize the layout of the layers in your HStack by adjusting its spacing in the Inspector panel.
★ Pro Tip
With the applicable layer(s) selected, you can use the keyboard shortcut ⌘⇧H to embed them in an HStack.