- bu is an event scope with Custom Dimension and collects all event occurs. (All Event include Ecommerce)
- Item category is the item scope and collects information about the product when an ecommerce event occurs. (Ecommerce Only)
The PDP data on the dashboard is aggregated based on the Item category.
1. This is a plp screen that lands after clicking on the promotion banner of lg.com/mx .

2. If you look at the GA event list (on the right side of the image) that occurs after the first product click, you can see that not only the view item, but also events such as at-impression and proactive message impression are executed.

3. For example, when you check the view item and the proactive message impression event during the event, you can see that the 'bu' and 'pdp' are the same as in the picture below, but the 'event category' data is different.
[view item]

[proactive message impression]

In this way, the use of bu Demand will include all traffic data aggregated as a number of events in a single landing page as shown above.

In conclusion, the 'bu' Dimension will contain all the traffic data aggregated in each event.
If you want to prevent session aggregation from multiple events and only view item events, use 'item category' instead of 'bu'.