The global collection cannot be directly queried. One cannot specify the global collection in a BQL query.

It is an virtual representation of global fields (learn more about global fields here).
This section will give the URL scheme and segmentation fields that are available on nearly all collections.

URL Scheme fields

The list of URL scheme fields, their slug and type:

Name	Slug	Type
URL	`url`	String
Protocol	`protocol`	String
Host	`host`	String
Path	`path`	String
Extension	`extension`	String
Query String	`query_string`	String
Query String Keys	`query_string_keys`	List

Segmentation fields

If your project defines a segmentation, it will also be accessible throughout all collections.

Each segment dimension has a name, that will be adapted for the slug.
A popular segment name is pagetype, used for the example below.

Name	Slug	Type
Pagetype	`segments.pagetype.value`	Tree
Pagetype Depth 1	`segments.pagetype.depth_1`	String
Pagetype Depth 2	`segments.pagetype.depth_2`	String
Pagetype Depth 3	`segments.pagetype.depth_3`	String
...	...	...

To filter on tree types, see Predicates.