Narrowing down facet count

[
    {
        "title": "Title 1",
        "tag_category":[
            {
                "tag": "Tag 1",
                "category": "Category 1"                    
            },
            {
                "tag": "Tag 2",
                "category": "Category 2"  
            },
            {
                "tag": "Tag 3",
                "category": "Category 1"  
            }
        ]
    },
    {
        "title": "Title 2",
        "tag_category":[
            {
                "tag": "Tag 1",
                "category": "Category 4"                    
            },
            {
                "tag": "Tag 4",
                "category": "Category 2"  
            },
            {
                "tag": "Tag 5",
                "category": "Category 1"  
            }
        ]
    }
]

here is a sample data of 2 records. I wanted to filter so that for example when I select Category 1 it narrows down to Tag 1 ,Tag 3 and Tag 5 counts as 1. Simply I want to get the tags used by a certain Category.

When I add tag_category.tag and tag_category.category attributes as facets then I still see all values for the tags when I select a category.

Is there a way to achieve this. Either inside Algolia itself or changing structure of data.

Thanks