Thanks for reading the topic.
Now I am showing how you can build a database relationship.
Step-1
Lets create any form that can be called "AbcX"
create a module selecting by the form "AbcX"
Create a Menu for admin panel for that "AbcX" module
Step-2
Lets create another form that can be name Xyz (please drag a select box).
Create a module selecting by the form Xyz. Once you select the form xyz at the bottom you can see Source from from dropdowns : AbcX ----> Form Field ---> Country name
than Submit and complete the module builder process
Create a Menu for admin panel for that "xyz" module
Step-3
login admin panel
you can see two menu one is AbcX and xyz
click AbcX
Create new
you can see last field called Country name.
Create some data
Step-4
click xyz menu
create new
you can see a dropdown button
what ever you keyin previous menu "AbcX" in country fied
You can see here at the dropdowns
Attached image.
Enjoy
