A root index space is the index space for all spaces.

Set the search-space space property to @all. Then all searches without specifying a space as query constraint will automatically refer to all spaces on a Confluence server.

Use space-local to not export the search space of the index space.

A space may only be defined as an index space for a subset of spaces on a Confluence server. This group of spaces is created by sharing the same space label (e.g my-label).

The Display Table Macro allows to select the search space by refering to that space label (e.g #my-label).

To use a space group as the default search space, set the seach-space space property to reference the space label of the group (e.g #my-label).