How to Create Custom Event Properties from Nested List Items in Event Data?

Hey there, I have been using Custom Event Properties to make analysis simpler for business users. A lot of times our events will have a list of objects as a data type. For eg : products.

"products": [
    	{
    		"product_id":"a1D671236980MRRAsEAP",
    		"quantity" : 1, 
    		"source": "browse_all"
    	},...]

I would like to create a custom event property that, let's say in this example points to the property source . Unfortunately, when creating a custom property, the property picker doesn't let me pick a property inside a list. I can use that property as a breakdown/filter but I can't create a custom property out of it. Is there a work around for this?