Need some explanation on what we call "settlement layer"

Let's talk about an use case of Bitcoin Cash, that is for remittances. This is how I think BCH would be used:

• An expat earns money in her local currency, then use those money to buy BCH.
• She sends those BCH to her family in her hometown.
• Her family then sells BCH for fiat.

Is BCH in this use case considered a settlement layer?