Get data from admin screen

Hello, I want to create a app that have user function, and admin function. So, how to retrieve data from one user only. not all data from FirebaseDB? and how retrieve data from admin, such as a keyword was setup from admin interface, and only data under that keyword get to user?

query your firebase data at the node for that user:

getValue - users/user1

You can also use the web component to do this (though more complicated with security rules in place)

Similarly, to return any data created by the admin, just query the data under the admin node