Suggest scope with multiple spaces or tree selector excluding spaces


I would like to make a custom form to select a page. I only want the user to be able to select a page in the form from a set of spaces. Is it correct that you can only provide one space in the data-search-scope?

An other option would be to select a document from a tree and insert the document in the input besides the tree (or modal), again with only documents in a set of spaces.

Is there an example of this, somewhere?

With regards