How to Select a data block's user in outliner??

Support Basics & Interface
1

https://thumbs.gfycat.com/TanInfamousImperatorangel-size_restricted.gif

How to Select data block’s user in outliner??
Nothing happens with my gesture on the gif.
And how to I know users in other scenes?

2

That’s a good question. I hope someone can answer this.