Power BI slicer (select 1 for multiple selection)

Hi,

I'm trying to replicate this dashboard https://www.freshbi.com/blogs/financials-in-powerbi-version-2

I need help for the following problem:

I am trying to recreate this "Level Selector" slicer where basically it collapsed and expands the rows. 

If Level Selector = 1, then it will only show the headers and totals

If Level Selector = 2, then it will show headers, sub-rows and totals

If Level Selector = 3, then it will show all. 

This website shows partially how to recreate this dashboard. But I am stuck as to how they are able to connect from the data source to the power bi. 

They used "TYPENUM" column [referring to the 2nd picture below] to  ‘collapse’ groups of rows. For example, we will be able to only show rows 9, 18, 19, 23, 24 from the range 8 - 25 when we choose level 2 later on.

Can anyone help, how do I move forward after numbering the "FORMATTEDTITLE" column using "TYPENUM" column? How do I relate that to the slicer so that when I click "2", it shows rows with TYPENUM = 1 and TYPENUM = 2, etc?