Adding data to ArcGIS Hub and restrict usage only to Organisation

[BenasPekarskis1]

Hello All, 

We are planning to use Arcgis online Data Hub to share the information about the data within our organisation. 

I have few questions, if I may ask:

1. Is it possible to restrict access to the data so it is visible only to the organisation and only people in organisation are able to view the data? 

2. What does it mean Update The Index? What this function does? 

3. How can I add data so it is searchable to all users of organisation.? On our site we want to use 'Search for data widget', but when we search for data, it does not find anything at all. What is the process to add data so it is visible?

Regards,

Ben