Using DXP Toolkit's powerful user meta rule, you are able to easily target a subset of your logged-in audience using the relevant user meta connected to each account.
For this example, let's assume you are tracking the audience segment subscribed to your newsletter with a user meta, labeled newsletter_subscription. Since you have multiple newsletters, this user meta may take the value of "weekly" or "monthly".
Now, to create a persona rule targeting the entire audience subscribed to any of your newsletters, you will have to create a new persona rule of the user meta type, and give a user meta key value of newsletter_subscription.
Leaving the value of the selected user meta empty will target all logged-in users that have a user meta labeled newsletter_subscription added to their profile, regardless of its value.
If instead you would like to target only the monthly newsletter subscribers, you can instead fill out the user meta value field with its respective value, in this case that value would be monthly.