Hey @Rahul thanks for a better question description.
Subelements goes through a list of dictionaries and then traverses a list with a given (nested sub-)key inside of those records.
Here the nested list is over the variable users
- name: alice
- name: bob
ietm.0 refers the the first item in the list, in this case the username Alice and item.1 to Bob.
So when you encounter
item.0.name - it refers to Alice
item.0.mysql.password - refers to the mysql password of Alice and so on.