BleveSearch - How to implement global search

Question

I have been using Bleve Search (Go Based search) for my application and I love the way it works, but I am stuck as how to implement global search using bleve.

Here is my use case:

Create an Index depending upon the Entity:

1. School
2. Teachers
3. Students
4. HOD

Bleve creates a folder and store the index file inside the folder. I am able to get the result if I search for School info in the School index folder by opening the index for school and do a search.

My question is how to do a global search. Meaning I am not sure which entity to search and want to get results from School, teachers etc. In order to start the Search I have to open the index using the path.

// open a new index
mapping := bleve.NewIndexMapping()
index, err := bleve.New("example.bleve", mapping) // DNadar -  How can we specify for global search?

http://www.blevesearch.com/docs/Getting%20Started/