Representing ratio between two indexes or visualization

Let's suppose I have two indexes and one visualization for each one:

IndexA with unique count of views per week
IndexB with unique count of likes per week

I would like to create a third visualization that is the ratio of views/likes for every week.
How can I do this?

Use the Math aggregation in the Visual Builder visualization. It will allow you to do most math operations on metrics.

I'm sorry. Can you be a little more specific? I tried with the Visual Builder filter ratio option but no luck.

Use the Math option in the aggregations.

Thanks but I don't know if that applies to my case. I can't add a math aggregation before applying filters.

Besides the previous structure, I'm also applying filters to get specific elements and I want to divide the two series after. I'm trying with both timelion and the visual builder.

I'm including screenshots: