Creating drill-down visuals where parts do not sum to the level above

[AaronClements]

Prefacing this by saying that I'm a Power BI noob and that I searched this forum for the answer to this question to no avail, so apologies for what might be a rookie question.

I'm working with about 6 data tables that represent sales areas of a store--each table containing a column for the number of transactions for that area. My issue is that the sum of transactions for a single sales area will not (and should not) sum to the amount displayed at the level above. 

For example, if I have a customer who makes a purchase of batteries and HDMI cables, it counts as 1 transaction for batteries and 1 transaction for HDMI cables. However, these products both fall under the Electronics department of my store, and the Electronics department receives credit for 1 transaction (batteries and HDMI cables together).

I would like to create a visual that allows me to see the number of transactions for my Electronics department, drill into it, and see the number of transactions for each category in that department, despite the sum of those categories not equaling the department amount. I have the number of transactions for every hierarchal level that I need--I just need a way to visualize it.

Here's an example of the least granular levels of my data tables below. Keep in mind that there are 4 tables that are more granular than Table 2--the last table (product-level) having thousands of rows:

Table 1:
Merchandise Type	Transactions
General Merchandise	12
Food	13

Table 2
Merchandise Type	Department	Transactions
General Merchandise	Electronics	10
General Merchandise	Home	2
General Merchandise	Apparel	5
Food	Fresh Food	10
Food	Freezer	5
Food	Beverages	8

Any help would be appreciated. Thanks in advance!

[Jorgast · Accepted solution]

Since the Transaction data is different based on the department vs the transaction, i would just break it up.

1. I would create a slicer for the Mechandise Type

2. Create a card that has the sum of Transactions or a table that shows the Merchandise type and the sum of each transaction. I would call the table Mechandise Type

3. Create a table that shows the department and the sum of transaction. I would call the table Transaction by Department

I am sure there is a better way, than my suggestion. hopefully this gives you an idea