Buttons and we links

Hello:

I havent used PBI for a while and I am getting confused with the new button set up. 

Situation: I have several PBI works books loaded in my app (premium account) and I want to create a button to do page navigation. My workbooks are in hierachy (i.e pbix1-->pbix2-->pbix3-->pbix4). Each pbix is a different file and I have used navigation (sections) to create a hierachy. 

Question 1: How do I add text to a Button. All I see is this. I can add a title, but not a text in the middle of the button. 

Question 2: Ok so I know that you probably do an action (Web URL) to link to another powerbi report. But Where do you get the link for each pbix?