How to filter/return selected values from Parameter selection

[Revelio]

Apologies for a Power BI newbie here:

I have a parameter that controls 4 charts relating to sales/profit (the 4 charts are Spend, Transactions, Customers and Average Spend) 

I have 4 levels of granularity in my data:
Category
Region
Sub-Region
Merchant 

I have 'All' values within the columns (which is a total of all other values in that column), as well as the individual named elements (e.g. under Region I have UK, USA, Canada, All). So if I use the parameter to select a Category, all the values in my charts will be duplicated. How do I create a condition on my 4-level parameter that if a parameter choice is made, the next level down should only include the "All" value? 

Is this able to be done by IF statement columns/measures?

I would like there to be the following structure in the returned data when a parameter choice is made:

• Parameter selection = Category    Category, Region = "All", Sub-Region = "All", Merchant = "All"
• Parameter selection = Region       Category = "All", Region, Sub-Region = "All", Merchant = "All"
• Parameter selection = Sub-Region       Category = "All", Region = "All", Sub-Region, Merchant = "All"
• Parameter selection = Merchant       Category = "All", Region = "All", Sub-Region = "All", Merchant
  
  
  Thanks in advance for any suggestions

[lbendlin]

Please provide sample data that covers your issue or question completely, in a usable format (not as a screenshot).
https://community.powerbi.com/t5/Community-Blog/How-to-provide-sample-data-in-the-Power-BI-Forum/ba-...
Please show the expected outcome based on the sample data you provided.

https://community.powerbi.com/t5/Desktop/How-to-Get-Your-Question-Answered-Quickly/m-p/1447523