Best practices
Extend content beneath the sidebar.
When possible, let people customize the contents of a sidebar.
Group hierarchy with disclosure controls if your app has a lot of content.
Consider using familiar symbols to represent items in the sidebar.
Consider letting people hide the sidebar.
In general, show no more than two levels of hierarchy in a sidebar.
If you need to include two levels of hierarchy in a sidebar, use succinct, descriptive labels to title each group.
Platform considerations
iOS
Avoid using a sidebar.
iPadOS
Consider using a tab bar first.
If necessary, apply the correct appearance to a sidebar.
macOS
Avoid stylizing your app by specifying a fixed color for all sidebar icons.
Consider automatically hiding and revealing a sidebar when its container window resizes.
Avoid putting critical information or actions at the bottom of a sidebar.
visionOS
If your app’s hierarchy is deep, consider using a sidebar within a tab in a tab bar.
For the complete guidance, including worked examples and illustrations, see the canonical page: https://developer.apple.com/design/human-interface-guidelines/sidebars