Need Help Creating DAX Logic using Selected Value from Slicer Based on Table with No Relationships

[GBlair]

I'm new to Power BI and DAX.
I have a sales dataset and need to create a dashboard where users can select from a dropdown to group customers into "Bought" and "Did not Buy" buckets. The dropdown is custom and can contain individual products, product families, or groups of product families.
They can only select one item from the dropdown.

When they select an item the customer id is placed into the "bought" or "did not buy" bucket.

I modified what I think is a standard PowerBI "Financial Sample" spreadsheet.

I added Cust_ID and Product Family columns (sample below).

Here's what I need to be able to do:

The Sales column is total sales (all products) of customers that bought any Furniture product.
The L1 Sales are just the sales of any furniture product.
Thanks for your help, and let me know if I'm not making any sense.