Any data source can be linked to an application by clicking 
from the application’s page:
The upper section allows you to filter the data sources:
Filter by Data Source types: Enable or disable the types to list (by default, all types are displayed)
Show linked data sources only: If this option is enabled, only data sources that are already linked are displayed. This is the case after clicking "Linked Data Source" for the first time.
You can also enter a text to search, which will be used to search the data source name, type, asset type, status and point name.
Use the
/
toogle to link / unlink a data source. Multiple data sources can be linked to an application without leaving your search results. Note: A data source can not be unlinked while it’s used by at least one widget, preventing widgets from being accidentally broken:
Use the
icon to pin your most-used data sources so they always appear at the top of the list. Note: this is a global action and affects all users.Each data source line is expandable, to display details about its definition:
Click
to view the data before using it in widgets:
Note: When a view does not contain any widgets, two other methods are proposed for linking data sources:
is equivalent to 
Clicking
on “Quick Start” is a shortcut to link data sources marked as favorites, for the application’s asset types:
