Kinesis Data Stream. Scaling and filtering

I have Kinesis Data Streams in one region and consumers in number of another regions. Consumers should receive messages regardless of whether they are delivered to other regions. Also consumers can be scaled in and out. Please advise how I can do the following

1. Ensure that each consumer only read messages to which it's subscribed and doesn't read messages to which it shouldn't have access
2. Scale Kinesis Data Stream based on consumer scaling. For example, consumer scaled-out by adding additional pod and then KDS adds more shards to the stream.