Question about "Components using other Licenses"

[binEncoder]

At https://docs.zephyrproject.org/latest/introduction/index.html#licensing, we've noticed that Zephyr licenses some non-Apache 2.0 components separately. However, it has some limitations: imported, reused and zephyr project.
I'd like to ask the following three questions.

1. How does the Zephyr community judge what is imported or reused?
2. Which are the components of the Zephyr Project?
3. Is littlefs imported or reused, and Is littlefs a component of Zephyr Project?

The above problem is what I want to consult when I want to use the settings littlefs combination, and I find that Zephyr does not mention the licence information of littlefs at https://docs.zephyrproject.org/latest/LICENSING.html#zephyr-licensing.
Judging from https://github.com/zephyrproject-rtos/littlefs, does littlefs use the BSD-3 licence. Does it not meet the conditions of "in some places there is no LICENSE file or way to put a LICENSE file there", so the community does not propose it separately to explain?
Finally, thanks to Zephyr for the very detailed documentation and instructions to get started.