How to filter attributes in Informatica Data Hub

I'm using for a project for the very first time Informatica Data Hub. We are using it to connect some sources with target systems in a publisher/subscription mode. Now, we have a requirement to create a filter process to meet the following requirements:

• Filter option for data based on attributes. Some subscribers will only get specific data from the topics.
• Filter option which attributes are shown in the subscription. Some subscribers will only get specific attributes from each topic.

I'm reading documentation of Informatica, and I know how to add filtering options using PowerCenter expressions for attributes using the subscription properties. However, I cannot find anything regarding point c, how can I make that a specific subscription is only consuming specific attributes of a topic?

Attributes can be filtered using filter transformation.

When you get the messages from the topic, either in json/ csv format, each attribute of a topic will have an identifier, technically a column name. Get the messages from the topic and pass it through an expression transformation where you can align all the identifiers. Then pass the pipeline to the filter transformation and filter out the records as required and pass it to the target.

If you provide example of few messages from the topic, can help you in detail on this